diff --git a/lib/Slic3r/GUI/Tab.pm b/lib/Slic3r/GUI/Tab.pm
index 3c44322b2e..b87249501a 100644
--- a/lib/Slic3r/GUI/Tab.pm
+++ b/lib/Slic3r/GUI/Tab.pm
@@ -558,6 +558,7 @@ sub build {
         top_infill_extrusion_width support_material_extrusion_width
         infill_overlap bridge_flow_ratio
         clip_multipart_objects xy_size_compensation threads resolution
+        wipe_tower wipe_tower_x wipe_tower_y wipe_tower_width wipe_tower_per_color_wipe
     ));
     $self->{config}->set('print_settings_id', '');
     
@@ -720,6 +721,14 @@ sub build {
             $optgroup->append_single_option_line('ooze_prevention');
             $optgroup->append_single_option_line('standby_temperature_delta');
         }
+        {
+            my $optgroup = $page->new_optgroup('Wipe tower');
+            $optgroup->append_single_option_line('wipe_tower');
+            $optgroup->append_single_option_line('wipe_tower_x');
+            $optgroup->append_single_option_line('wipe_tower_y');
+            $optgroup->append_single_option_line('wipe_tower_width');
+            $optgroup->append_single_option_line('wipe_tower_per_color_wipe');
+        }
         {
             my $optgroup = $page->new_optgroup('Advanced');
             $optgroup->append_single_option_line('interface_shells');
@@ -955,6 +964,10 @@ sub _update {
     my $have_ooze_prevention = $config->ooze_prevention;
     $self->get_field($_)->toggle($have_ooze_prevention)
         for qw(standby_temperature_delta);
+
+    my $have_wipe_tower = $config->wipe_tower;
+    $self->get_field($_)->toggle($have_wipe_tower)
+        for qw(wipe_tower_x wipe_tower_y wipe_tower_width wipe_tower_per_color_wipe);
 }
 
 sub hidden_options { !$Slic3r::have_threads ? qw(threads) : () }
@@ -969,7 +982,7 @@ sub build {
     my $self = shift;
     
     $self->init_config_options(qw(
-        filament_colour filament_diameter filament_notes filament_max_volumetric_speed extrusion_multiplier filament_density filament_cost
+        filament_colour filament_diameter filament_type filament_soluble filament_notes filament_max_volumetric_speed extrusion_multiplier filament_density filament_cost
         temperature first_layer_temperature bed_temperature first_layer_bed_temperature
         fan_always_on cooling
         min_fan_speed max_fan_speed bridge_fan_speed disable_fan_first_layers
@@ -984,6 +997,8 @@ sub build {
             $optgroup->append_single_option_line('filament_colour', 0);
             $optgroup->append_single_option_line('filament_diameter', 0);
             $optgroup->append_single_option_line('extrusion_multiplier', 0);
+            $optgroup->append_single_option_line('filament_type', 0);
+            $optgroup->append_single_option_line('filament_soluble', 0);
             $optgroup->append_single_option_line('filament_density', 0);
             $optgroup->append_single_option_line('filament_cost', 0);
         }
@@ -1137,7 +1152,7 @@ sub build {
         octoprint_host octoprint_apikey
         use_firmware_retraction
         use_volumetric_e variable_layer_height
-        start_gcode end_gcode before_layer_gcode layer_gcode toolchange_gcode
+        single_extruder_multi_material start_gcode end_gcode before_layer_gcode layer_gcode toolchange_gcode
         nozzle_diameter extruder_offset
         retract_length retract_lift retract_speed retract_restart_extra retract_before_travel retract_layer_change wipe
         retract_length_toolchange retract_restart_extra_toolchange
@@ -1198,6 +1213,7 @@ sub build {
                     min         => 1,
                 );
                 $optgroup->append_single_option_line($option);
+                $optgroup->append_single_option_line('single_extruder_multi_material');
             }
             $optgroup->on_change(sub {
                 my ($opt_id) = @_;
@@ -1538,6 +1554,7 @@ sub _update {
     
     my $have_multiple_extruders = $self->{extruders_count} > 1;
     $self->get_field('toolchange_gcode')->toggle($have_multiple_extruders);
+    $self->get_field('single_extruder_multi_material')->toggle($have_multiple_extruders);
     
     for my $i (0 .. ($self->{extruders_count}-1)) {
         my $have_retract_length = $config->get_at('retract_length', $i) > 0;
diff --git a/xs/src/libslic3r/GCode.cpp b/xs/src/libslic3r/GCode.cpp
index ce0be2ec88..7b3def024f 100644
--- a/xs/src/libslic3r/GCode.cpp
+++ b/xs/src/libslic3r/GCode.cpp
@@ -2,6 +2,7 @@
 #include "ExtrusionEntity.hpp"
 #include "EdgeGrid.hpp"
 #include "Geometry.hpp"
+#include "GCode/WipeTowerPrusaMM.hpp"
 
 #include <algorithm>
 #include <cstdlib>
@@ -384,6 +385,8 @@ bool GCode::do_export(FILE *file, Print &print)
                     // Set first layer extruder.
                     this->_print_first_layer_extruder_temperatures(file, print, false);
                 }
+                // Get optimal tool ordering to minimize tool switches of a multi-exruder print.
+                std::vector<ToolOrdering::LayerTools> tool_ordering = ToolOrdering::tool_ordering(*object);
                 // Pair the object layers with the support layers by z, extrude them.
                 size_t idx_object_layer  = 0;
                 size_t idx_support_layer = 0;
@@ -401,7 +404,9 @@ bool GCode::do_export(FILE *file, Print &print)
                             -- idx_object_layer;
                         }
                     }
-                    this->process_layer(file, print, layers_to_print, &copy - object->_shifted_copies.data());
+                    auto it_layer_tools = std::lower_bound(tool_ordering.begin(), tool_ordering.end(), ToolOrdering::LayerTools(layer_to_print.layer()->print_z));
+                    assert(it_layer_tools != tool_ordering.end() && it_layer_tools->print_z == layer_to_print.layer()->print_z);
+                    this->process_layer(file, print, layers_to_print, *it_layer_tools, &copy - object->_shifted_copies.data());
                 }
                 write(file, this->filter(m_cooling_buffer->flush(), true));
                 ++ finished_objects;
@@ -437,21 +442,63 @@ bool GCode::do_export(FILE *file, Print &print)
             }
             ++ object_order;
         }
+        // Get optimal tool ordering to minimize tool switches of a multi-exruder print.
+        std::vector<ToolOrdering::LayerTools> tool_ordering = ToolOrdering::tool_ordering(print);
+        // Prusa Multi-Material wipe tower.
+        if (print.config.single_extruder_multi_material.value && print.config.wipe_tower.value && 
+            ! tool_ordering.empty() && tool_ordering.front().wipe_tower_partitions > 0) {
+            // Initialize the wipe tower.
+            auto *wipe_tower = new WipeTowerPrusaMM(
+                    float(print.config.wipe_tower_x.value), float(print.config.wipe_tower_y.value), 
+                    float(print.config.wipe_tower_width.value), float(print.config.wipe_tower_per_color_wipe.value));
+            //wipe_tower->set_retract();
+            //wipe_tower->set_zhop();
+            //wipe_tower->set_zhop();
+            // Set the extruder & material properties at the wipe tower object.
+            for (size_t i = 0; i < 4; ++ i)
+                wipe_tower->set_extruder(
+                    i, 
+                    WipeTowerPrusaMM::parse_material(print.config.filament_type.get_at(i).c_str()),
+                    print.config.temperature.get_at(i),
+                    print.config.first_layer_temperature.get_at(i));
+            m_wipe_tower.reset(wipe_tower);
+        }
         // Extrude the layers.
-        for (auto &layer : layers)
+        for (auto &layer : layers) {
             // layer.second is of type std::vector<LayerToPrint>,
             // wher the objects are sorted by their sorted order given by object_indices.
-            this->process_layer(file, print, layer.second);
+            auto it_layer_tools = std::lower_bound(tool_ordering.begin(), tool_ordering.end(), ToolOrdering::LayerTools(layer.first));
+            assert(it_layer_tools != tool_ordering.end() && layer.first);
+            if (m_wipe_tower) {
+                bool first_layer = layer.first == layers.begin()->first;
+                auto it_layer_tools_next = it_layer_tools;
+                ++ it_layer_tools_next;
+                m_wipe_tower->set_layer(
+                    layer.first, 
+                    first_layer ? 
+                        print.objects.front()->config.first_layer_height.get_abs_value(print.objects.front()->config.layer_height.value) :
+                        print.objects.front()->config.layer_height.value,
+                    it_layer_tools->wipe_tower_partitions,
+                    first_layer,
+                    it_layer_tools->wipe_tower_partitions == 0 || (it_layer_tools_next == tool_ordering.end() || it_layer_tools_next->wipe_tower_partitions == 0));
+            }
+            this->process_layer(file, print, layer.second, *it_layer_tools, size_t(-1));
+        }
         write(file, this->filter(m_cooling_buffer->flush(), true));
     }
 
     // write end commands to file
-    write(file, this->retract());   // TODO: process this retract through PressureRegulator in order to discharge fully
+    if (m_wipe_tower) {
+        // Unload the current filament over the purge tower.
+        write(file, this->wipe_tower_tool_change(-1));
+        m_wipe_tower.release();
+    } else
+        write(file, this->retract());   // TODO: process this retract through PressureRegulator in order to discharge fully
     write(file, m_writer.set_fan(false));
     writeln(file, m_placeholder_parser.process(print.config.end_gcode));
     write(file, m_writer.update_progress(m_layer_count, m_layer_count, true)); // 100%
     write(file, m_writer.postamble());
-    
+
     // get filament stats
     print.filament_stats.clear();
     print.total_used_filament    = 0.;
@@ -543,6 +590,7 @@ void GCode::process_layer(
     const Print                     &print,
     // Set of object & print layers of the same PrintObject and with the same print_z.
     const std::vector<LayerToPrint> &layers,
+    const ToolOrdering::LayerTools  &layer_tools,
     // If set to size_t(-1), then print all copies of all objects.
     // Otherwise print a single copy of a single object.
     const size_t                     single_object_idx)
@@ -562,7 +610,8 @@ void GCode::process_layer(
     }
     const Layer         &layer         = (object_layer != nullptr) ? *object_layer : *support_layer;    
     coordf_t             print_z       = layer.print_z;
-    bool                 first_layer   = print_z < m_config.first_layer_height.get_abs_value(m_config.layer_height.value) + EPSILON;
+    bool                 first_layer   = layer.id() == 0;
+    unsigned int         first_extruder_id = layer_tools.extruders.empty() ? 0 : layer_tools.extruders.front();
 
     // Initialize config with the 1st object to be printed at this layer.
     m_config.apply(layer.object()->config, true);
@@ -620,7 +669,7 @@ void GCode::process_layer(
     if (! m_brim_done)
         // Switch the extruder to the extruder of the perimeters, so the perimeters extruder will be primed
         // by the skirt before the brim is extruded with the same extruder.
-        gcode += this->set_extruder(print.regions.front()->config.perimeter_extruder.value - 1);
+        gcode += this->set_extruder(layer_tools.extruders.front());
     
     // Extrude skirt at the print_z of the raft layers and normal object layers
     // not at the print_z of the interlaced support material layers.
@@ -643,10 +692,10 @@ void GCode::process_layer(
             std::vector<unsigned int> extruder_ids = m_writer.extruder_ids();
             // Reorder the extruders, so that the last used extruder is at the front.
             for (size_t i = 1; i < extruder_ids.size(); ++ i)
-                if (extruder_ids[i] == m_writer.extruder()->id) {
+                if (extruder_ids[i] == first_extruder_id) {
                     // Move the last extruder to the front.
                     memmove(extruder_ids.data() + 1, extruder_ids.data(), i * sizeof(unsigned int));
-                    extruder_ids.front() = m_writer.extruder()->id;
+                    extruder_ids.front() = first_extruder_id;
                     break;
                 }
             size_t n_loops = print.skirt.entities.size();
@@ -668,7 +717,7 @@ void GCode::process_layer(
             }
         } else
             // Extrude all skirts with the current extruder.
-            skirt_loops_per_extruder[m_writer.extruder()->id] = std::pair<size_t, size_t>(0, print.config.skirts.value);
+            skirt_loops_per_extruder[first_extruder_id] = std::pair<size_t, size_t>(0, print.config.skirts.value);
     }
 
     // Group extrusions by an extruder, then by an object, an island and a region.
@@ -684,12 +733,12 @@ void GCode::process_layer(
                 // Don't change extruder if the extruder is set to 0. Use the current extruder instead.
                 bool single_extruder = 
                     (object.config.support_material_extruder.value == object.config.support_material_interface_extruder.value ||
-                    (object.config.support_material_extruder.value == int(m_writer.extruder()->id) && object.config.support_material_interface_extruder.value == 0) ||
-                    (object.config.support_material_interface_extruder.value == int(m_writer.extruder()->id) && object.config.support_material_extruder.value == 0));
+                    (object.config.support_material_extruder.value == int(first_extruder_id) && object.config.support_material_interface_extruder.value == 0) ||
+                    (object.config.support_material_interface_extruder.value == int(first_extruder_id) && object.config.support_material_extruder.value == 0));
                 // Assign an extruder to the base.
                 ObjectByExtruder &obj = object_by_extruder(
                     by_extruder,
-                    (object.config.support_material_extruder == 0) ? m_writer.extruder()->id : (object.config.support_material_extruder - 1),
+                    (object.config.support_material_extruder == 0) ? first_extruder_id : (object.config.support_material_extruder - 1),
                     &layer_to_print - layers.data(),
                     layers.size());
                 obj.support = &support_layer.support_fills;
@@ -697,7 +746,7 @@ void GCode::process_layer(
                 if (! single_extruder) {
                     ObjectByExtruder &obj_interface = object_by_extruder(
                         by_extruder,
-                        (object.config.support_material_interface_extruder == 0) ? m_writer.extruder()->id : (object.config.support_material_interface_extruder - 1),
+                        (object.config.support_material_interface_extruder == 0) ? first_extruder_id : (object.config.support_material_interface_extruder - 1),
                         &layer_to_print - layers.data(),
                         layers.size());
                     obj_interface.support = &support_layer.support_fills;
@@ -793,31 +842,14 @@ void GCode::process_layer(
         }
     } // for objects
 
-    // Tweak extruder ordering to save toolchanges.
-    std::vector<unsigned int> extruders;
-    extruders.reserve(by_extruder.size());
-    for (const auto &ex : by_extruder)
-        extruders.push_back(ex.first);
-    if (extrude_skirt) {
-        // Merge with the skirt extruders.
-        for (const auto &ex : skirt_loops_per_extruder)
-            extruders.push_back(ex.first);
-        sort_remove_duplicates(extruders);
-    }
-    // Reorder the extruders, so that the last used extruder is at the front.
-    for (size_t i = 1; i < extruders.size(); ++ i)
-        if (extruders[i] == m_writer.extruder()->id) {
-            // Move the last extruder to the front.
-			memmove(extruders.data() + 1, extruders.data(), i * sizeof(unsigned int));
-            extruders.front() = m_writer.extruder()->id;
-            break;
-        }
     // Extrude the skirt, brim, support, perimeters, infill ordered by the extruders.
     std::vector<std::unique_ptr<EdgeGrid::Grid>> lower_layer_edge_grids(layers.size());
-    for (unsigned int extruder_id : extruders)
+    for (unsigned int extruder_id : layer_tools.extruders)
     {
         gcode += this->set_extruder(extruder_id);
-        //FIXME here will come the priming tower call.
+        if (m_wipe_tower && ! m_wipe_tower->finished() && extruder_id == layer_tools.extruders.back())
+            // Last extruder change on the layer or no extruder change at all.
+            m_wipe_tower->close_layer();
 
         if (extrude_skirt) {
             auto loops_it = skirt_loops_per_extruder.find(extruder_id);
@@ -1675,7 +1707,7 @@ std::string GCode::_extrude(const ExtrusionPath &path, std::string description,
     this->set_last_pos(path.last_point());
     
     if (m_config.cooling)
-        m_elapsed_time += path_length / F * 60;
+        m_elapsed_time += path_length / F * 60.f;
     
     return gcode;
 }
@@ -1814,21 +1846,39 @@ std::string GCode::set_extruder(unsigned int extruder_id)
         gcode += pp.process(m_config.toolchange_gcode.value) + '\n';
     }
     
-    // if ooze prevention is enabled, park current extruder in the nearest
-    // standby point and set it to the standby temperature
-    if (m_ooze_prevention.enable && m_writer.extruder() != NULL)
-        gcode += m_ooze_prevention.pre_toolchange(*this);
-    
-    // append the toolchange command
-    gcode += m_writer.toolchange(extruder_id);
-    
-    // set the new extruder to the operating temperature
-    if (m_ooze_prevention.enable)
-        gcode += m_ooze_prevention.post_toolchange(*this);
+    if (m_wipe_tower) {
+        assert(! m_wipe_tower->finished());
+        if (! m_wipe_tower->finished())
+            gcode += this->wipe_tower_tool_change(extruder_id);
+    } else {
+        // if ooze prevention is enabled, park current extruder in the nearest
+        // standby point and set it to the standby temperature
+        if (m_ooze_prevention.enable && m_writer.extruder() != NULL)
+            gcode += m_ooze_prevention.pre_toolchange(*this);
+        // append the toolchange command
+        gcode += m_writer.toolchange(extruder_id);
+        // set the new extruder to the operating temperature
+        if (m_ooze_prevention.enable)
+            gcode += m_ooze_prevention.post_toolchange(*this);
+    }
     
     return gcode;
 }
 
+std::string GCode::wipe_tower_tool_change(int extruder_id)
+{
+    // Move over the wipe tower.
+    std::string gcode = m_writer.travel_to_xy(Pointf3(m_wipe_tower->position().x, m_wipe_tower->position().y));
+    gcode += m_writer.unlift();
+    // Let the tool change be executed by the wipe tower class.
+    std::pair<std::string, WipeTower::xy> code_and_pos = m_wipe_tower->tool_change(extruder_id);
+    // Inform the G-code writer about the changes done behind its back.
+    gcode += code_and_pos.first;
+    // A phony move to the end position at the wipe tower.
+    m_writer.travel_to_xy(Pointf(code_and_pos.second.x, code_and_pos.second.y));
+    return gcode;
+}
+
 // convert a model-space scaled point into G-code coordinates
 Pointf GCode::point_to_gcode(const Point &point) const
 {
diff --git a/xs/src/libslic3r/GCode.hpp b/xs/src/libslic3r/GCode.hpp
index 6601961299..4bba6866f7 100644
--- a/xs/src/libslic3r/GCode.hpp
+++ b/xs/src/libslic3r/GCode.hpp
@@ -13,6 +13,8 @@
 #include "GCode/CoolingBuffer.hpp"
 #include "GCode/PressureEqualizer.hpp"
 #include "GCode/SpiralVase.hpp"
+#include "GCode/ToolOrdering.hpp"
+#include "GCode/WipeTower.hpp"
 #include "EdgeGrid.hpp"
 
 #include <memory>
@@ -129,6 +131,7 @@ private:
         const Print                     &print,
         // Set of object & print layers of the same PrintObject and with the same print_z.
         const std::vector<LayerToPrint> &layers,
+        const ToolOrdering::LayerTools  &layer_tools,
         // If set to size_t(-1), then print all copies of all objects.
         // Otherwise print a single copy of a single object.
         const size_t                     single_object_idx = size_t(-1));
@@ -172,6 +175,7 @@ private:
     std::string     retract(bool toolchange = false);
     std::string     unretract() { return m_writer.unlift() + m_writer.unretract(); }
     std::string     set_extruder(unsigned int extruder_id);
+    std::string     wipe_tower_tool_change(int extruder_id);
 
     /* Origin of print coordinates expressed in unscaled G-code coordinates.
        This affects the input arguments supplied to the extrude*() and travel_to()
@@ -218,6 +222,7 @@ private:
     std::unique_ptr<CoolingBuffer>      m_cooling_buffer;
     std::unique_ptr<SpiralVase>         m_spiral_vase;
     std::unique_ptr<PressureEqualizer>  m_pressure_equalizer;
+    std::unique_ptr<WipeTower>          m_wipe_tower;
 
     // Heights at which the skirt has already been extruded.
     std::vector<coordf_t>               m_skirt_done;
diff --git a/xs/src/libslic3r/GCode/ToolOrdering.cpp b/xs/src/libslic3r/GCode/ToolOrdering.cpp
new file mode 100644
index 0000000000..b9240dabc3
--- /dev/null
+++ b/xs/src/libslic3r/GCode/ToolOrdering.cpp
@@ -0,0 +1,194 @@
+#include "ToolOrdering.hpp"
+
+namespace Slic3r {
+namespace ToolOrdering {
+
+// Collect extruders reuqired to print layers.
+static void collect_extruders(const PrintObject &object, std::vector<LayerTools> &layers)
+{
+    // Collect the support extruders.
+    for (auto support_layer : object.support_layers) {
+        auto it_layer = std::find(layers.begin(), layers.end(), LayerTools(support_layer->print_z));
+        assert(it_layer != layers.end());
+        ExtrusionRole role = support_layer->support_fills.role();
+        bool         has_support        = role == erMixed || role == erSupportMaterial;
+        bool         has_interface      = role == erMixed || role == erSupportMaterialInterface;
+        unsigned int extruder_support   = object.config.support_material_extruder.value;
+        unsigned int extruder_interface = object.config.support_material_interface_extruder.value;
+        if (has_support && has_interface) {
+            // If both base and interface supports are to be extruded and one of them will be extruded with a "don't care" extruder,
+            // print both with the same extruder to minimize extruder switches.
+            if (extruder_support == 0)
+                extruder_support = extruder_interface;
+            else if (extruder_interface == 0)
+                extruder_interface = extruder_support;
+        }
+        if (has_support)
+            it_layer->extruders.push_back(extruder_support);
+        if (has_interface)
+            it_layer->extruders.push_back(extruder_interface);
+    }
+    // Collect the object extruders.
+    for (auto layer : object.layers) {
+        auto it_layer = std::find(layers.begin(), layers.end(), LayerTools(layer->print_z));
+        assert(it_layer != layers.end());
+        // What extruders are required to print this object layer?
+        for (size_t region_id = 0; region_id < object.print()->regions.size(); ++ region_id) {
+            const LayerRegion *layerm = layer->regions[region_id];
+            if (layerm == nullptr)
+                continue;
+            const PrintRegion &region = *object.print()->regions[region_id];
+            if (! layerm->perimeters.entities.empty())
+                it_layer->extruders.push_back(region.config.perimeter_extruder.value);
+            bool has_infill       = false; 
+            bool has_solid_infill = false;
+            for (const ExtrusionEntity *ee : layerm->fills.entities) {
+                // fill represents infill extrusions of a single island.
+                const auto *fill = dynamic_cast<const ExtrusionEntityCollection*>(ee);
+                ExtrusionRole role = fill->entities.empty() ? erNone : fill->entities.front()->role();
+                if (is_solid_infill(role))
+                    has_solid_infill = true;
+                else if (role != erNone)
+                    has_infill = true;
+            }
+            if (has_solid_infill)
+                it_layer->extruders.push_back(region.config.solid_infill_extruder);
+            if (has_infill)
+                it_layer->extruders.push_back(region.config.infill_extruder);
+        }
+    }
+
+    // Sort and remove duplicates
+    for (LayerTools &lt : layers)
+        sort_remove_duplicates(lt.extruders);
+}
+
+// Reorder extruders to minimize layer changes.
+static void reorder_extruders(std::vector<LayerTools> &layers)
+{
+    if (layers.empty())
+        return;
+
+    // Initialize the last_extruder_id with the first non-zero extruder id used for the print.
+    unsigned int last_extruder_id = 0;
+    for (size_t i = 0; i < layers.size() && last_extruder_id == 0; ++ i) {
+        const LayerTools &lt = layers[i];
+        for (unsigned int extruder_id : lt.extruders)
+            if (extruder_id > 0) {
+                last_extruder_id = extruder_id;
+                break;
+            }
+    }
+    if (last_extruder_id == 0)
+        last_extruder_id = 1;
+
+    for (LayerTools &lt : layers) {
+        if (lt.extruders.empty())
+            continue;
+        if (lt.extruders.size() == 1 && lt.extruders.front() == 0)
+            lt.extruders.front() = last_extruder_id;
+        else {
+            if (lt.extruders.front() == 0)
+                // Pop the "don't care" extruder, the "don't care" region will be merged with the next one.
+                lt.extruders.erase(lt.extruders.begin());
+            // Reorder the extruders to start with the last one.
+            for (size_t i = 1; i < lt.extruders.size(); ++ i)
+                if (lt.extruders[i] == last_extruder_id) {
+                    // Move the last extruder to the front.
+                    memmove(lt.extruders.data() + 1, lt.extruders.data(), i * sizeof(unsigned int));
+                    lt.extruders.front() = last_extruder_id;
+                    break;
+                }
+        }
+        last_extruder_id = lt.extruders.back();
+    }
+
+    // Reindex the extruders, so they are zero based, not 1 based.
+    for (LayerTools &lt : layers)
+        for (unsigned int &extruder_id : lt.extruders) {
+            assert(extruder_id > 0);
+            -- extruder_id;
+        }
+}
+
+static void fill_wipe_tower_partitions(std::vector<LayerTools> &layers)
+{
+    if (layers.empty())
+        return;
+
+    // Count the minimum number of tool changes per layer.
+    for (LayerTools &lt : layers)
+        lt.wipe_tower_partitions = std::max<int>(0, int(layers.front().extruders.size()) - 1);
+
+    // In case a distinct set of tools are used between two layers, there will be an additional tool change at the start of a layer.
+    //FIXME this does not minimize the number of tool changes in worst case.
+    for (size_t i = 1; i < layers.size(); ++ i)
+        if (layers[i-1].extruders.back() != layers[i].extruders.front())
+            ++ layers[i].wipe_tower_partitions;
+
+    // Propagate the wipe tower partitions down to support the upper partitions by the lower partitions.
+    for (int i = int(layers.size()) - 2; i >= 0; -- i)
+        layers[i].wipe_tower_partitions = std::max(layers[i + 1].wipe_tower_partitions, layers[i].wipe_tower_partitions);
+}
+
+// For the use case when each object is printed separately
+// (print.config.complete_objects is true).
+std::vector<LayerTools> tool_ordering(PrintObject &object)
+{
+    // Initialize the print layers for just a single object.
+    std::vector<LayerTools> layers;
+    {
+        std::vector<coordf_t> zs;
+        zs.reserve(zs.size() + object.layers.size() + object.support_layers.size());
+        for (auto layer : object.layers)
+            zs.emplace_back(layer->print_z);
+        for (auto layer : object.support_layers)
+            zs.emplace_back(layer->print_z);
+        sort_remove_duplicates(zs);
+        for (coordf_t z : zs)
+            layers.emplace_back(LayerTools(z));
+    }
+
+    // Collect extruders reuqired to print the layers.
+    collect_extruders(object, layers);
+
+    // Reorder the extruders to minimize tool switches.
+    reorder_extruders(layers);
+
+    fill_wipe_tower_partitions(layers);
+    return layers;
+}
+
+// For the use case when all objects are printed at once.
+// (print.config.complete_objects is false).
+std::vector<LayerTools> tool_ordering(const Print &print)
+{
+    // Initialize the print layers for all objects and all layers. 
+    std::vector<LayerTools> layers;
+    {
+        std::vector<coordf_t> zs;
+        for (auto object : print.objects) {
+            zs.reserve(zs.size() + object->layers.size() + object->support_layers.size());
+            for (auto layer : object->layers)
+                zs.emplace_back(layer->print_z);
+            for (auto layer : object->support_layers)
+                zs.emplace_back(layer->print_z);
+        }
+        sort_remove_duplicates(zs);
+        for (coordf_t z : zs)
+            layers.emplace_back(LayerTools(z));
+    }
+
+    // Collect extruders reuqired to print the layers.
+    for (auto object : print.objects)
+        collect_extruders(*object, layers);
+
+    // Reorder the extruders to minimize tool switches.
+    reorder_extruders(layers);
+
+    fill_wipe_tower_partitions(layers);
+    return layers;
+}
+
+} // namespace ToolOrdering
+} // namespace Slic3r
diff --git a/xs/src/libslic3r/GCode/ToolOrdering.hpp b/xs/src/libslic3r/GCode/ToolOrdering.hpp
new file mode 100644
index 0000000000..0556f7e2ef
--- /dev/null
+++ b/xs/src/libslic3r/GCode/ToolOrdering.hpp
@@ -0,0 +1,38 @@
+// Ordering of the tools to minimize tool switches.
+
+#ifndef slic3r_ToolOrdering_hpp_
+#define slic3r_ToolOrdering_hpp_
+
+#include "libslic3r.h"
+#include "Print.hpp"
+
+namespace Slic3r {
+namespace ToolOrdering {
+
+struct LayerTools
+{
+    LayerTools(const coordf_t z) : print_z(z), wipe_tower_partitions(0) {}
+
+    bool operator< (const LayerTools &rhs) const { return print_z <  rhs.print_z; }
+    bool operator==(const LayerTools &rhs) const { return print_z == rhs.print_z; }
+
+	coordf_t 					print_z;
+	// Zero based extruder IDs, ordered to minimize tool switches.
+	std::vector<unsigned int> 	extruders;
+	// Number of wipe tower partitions to support the required number of tool switches
+	// and to support the wipe tower partitions above this one.
+    size_t                      wipe_tower_partitions;
+};
+
+// For the use case when each object is printed separately
+// (print.config.complete_objects is true).
+extern std::vector<LayerTools> tool_ordering(PrintObject &object);
+
+// For the use case when all objects are printed at once.
+// (print.config.complete_objects is false).
+extern std::vector<LayerTools> tool_ordering(const Print &print);
+
+} // namespace ToolOrdering
+} // namespace SLic3r
+
+#endif /* slic3r_ToolOrdering_hpp_ */
diff --git a/xs/src/libslic3r/GCode/WipeTower.hpp b/xs/src/libslic3r/GCode/WipeTower.hpp
new file mode 100644
index 0000000000..37a339cd31
--- /dev/null
+++ b/xs/src/libslic3r/GCode/WipeTower.hpp
@@ -0,0 +1,59 @@
+#ifndef slic3r_WipeTower_hpp_
+#define slic3r_WipeTower_hpp_
+
+#include <utility>
+#include <string>
+
+namespace Slic3r
+{
+
+// A pure virtual WipeTower definition.
+class WipeTower
+{
+public:
+	// Internal point class, to make the wipe tower independent from other slic3r modules.
+	// This is important for Prusa Research as we want to build the wipe tower post-processor independently from slic3r.
+	struct xy
+	{
+		xy(float x = 0.f, float y = 0.f) : x(x), y(y) {}
+		xy  operator+(const xy &rhs) const { xy out(*this); out.x += rhs.x; out.y += rhs.y; return out; }
+		xy  operator-(const xy &rhs) const { xy out(*this); out.x -= rhs.x; out.y -= rhs.y; return out; }
+		xy& operator+=(const xy &rhs) { x += rhs.x; y += rhs.y; return *this; }
+		xy& operator-=(const xy &rhs) { x -= rhs.x; y -= rhs.y; return *this; }
+		float x;
+		float y;
+	};
+
+	WipeTower() {}
+	virtual ~WipeTower() {}
+
+	// Return the wipe tower position.
+	virtual const xy& position() const = 0;
+
+	// The wipe tower is finished, there should be no more tool changes or wipe tower prints.
+	virtual bool 	  finished() const = 0;
+
+	// Switch to a next layer.
+	virtual void 	  set_layer(
+		// Print height of this layer.
+		float  print_z,
+		// Layer height, used to calculate extrusion the rate. 
+		float  layer_height, 
+		// Maximum number of tool changes on this layer or the layers below.
+		size_t max_tool_changes, 
+		// Is this the first layer of the print? In that case print the brim first.
+		bool   is_first_layer,
+		// Is this the last layer of the wipe tower?
+		bool   is_last_layer) = 0;
+
+	// Returns gcode for toolchange and the end position.
+	// if new_tool == -1, just unload the current filament over the wipe tower.
+	virtual std::pair<std::string, xy> tool_change(int new_tool) = 0;
+
+	// Close the current wipe tower layer with a perimeter and possibly fill the unfilled space with a zig-zag.
+	virtual std::pair<std::string, xy> close_layer() = 0;
+};
+
+}; // namespace Slic3r
+
+#endif /* slic3r_WipeTower_hpp_ */
diff --git a/xs/src/libslic3r/WipeTower.cpp b/xs/src/libslic3r/GCode/WipeTowerPrusaMM.cpp
similarity index 61%
rename from xs/src/libslic3r/WipeTower.cpp
rename to xs/src/libslic3r/GCode/WipeTowerPrusaMM.cpp
index b00263acf5..bce5e02479 100644
--- a/xs/src/libslic3r/WipeTower.cpp
+++ b/xs/src/libslic3r/GCode/WipeTowerPrusaMM.cpp
@@ -1,4 +1,4 @@
-#include "WipeTower.hpp"
+#include "WipeTowerPrusaMM.hpp"
 
 #include <assert.h>
 #include <math.h>
@@ -13,9 +13,11 @@
 #define strcasecmp _stricmp
 #endif
 
-namespace PrusaSingleExtruderMM
+namespace Slic3r
 {
 
+namespace PrusaMultiMaterial {
+
 class Writer
 {
 public:
@@ -171,18 +173,18 @@ public:
 		return *this;
 	};
 
-	Writer& comment_material(WipeTower::material_type material)
+	Writer& comment_material(WipeTowerPrusaMM::material_type material)
 	{
 		m_gcode += "; material : ";
 		switch (material)
 		{
-		case WipeTower::PVA:
+		case WipeTowerPrusaMM::PVA:
 			m_gcode += "#8 (PVA)";
 			break;
-		case WipeTower::SCAFF:
+		case WipeTowerPrusaMM::SCAFF:
 			m_gcode += "#5 (Scaffold)";
 			break;
-		case WipeTower::FLEX:
+		case WipeTowerPrusaMM::FLEX:
 			m_gcode += "#4 (Flex)";
 			break;
 		default:
@@ -236,6 +238,8 @@ private:
 	}
 };
 
+} // namespace PrusaMultiMaterial
+
 static inline int randi(int lo, int hi)
 {
 	int n = hi - lo + 1;
@@ -244,7 +248,7 @@ static inline int randi(int lo, int hi)
 	return lo + i;
 }
 
-WipeTower::material_type WipeTower::parse_material(const char *name)
+WipeTowerPrusaMM::material_type WipeTowerPrusaMM::parse_material(const char *name)
 {
 	if (strcasecmp(name, "PLA") == 0)
 		return PLA;
@@ -267,116 +271,58 @@ WipeTower::material_type WipeTower::parse_material(const char *name)
 	return INVALID;
 }
 
-std::string WipeTower::FirstLayer(bool sideOnly, float y_offset)
+std::pair<std::string, WipeTower::xy> WipeTowerPrusaMM::tool_change(int tool)
 {
-	const box_coordinates wipeTower_box(
-		m_wipe_tower_pos, 
-		m_wipe_tower_width, 
-		m_wipe_area * float(m_color_changes) - perimeterWidth / 2);
+	// Either it is the last tool unload,
+	// or there must be a nonzero wipe tower partitions available.
+	assert(tool < 0 || it_layer_tools->wipe_tower_partitions > 0);
 
-	Writer writer;
-	writer.set_extrusion_flow(extrusion_flow * 1.1f)
-		  // Let the writer know the current Z position as a base for Z-hop.
-		  .set_z(m_z_pos)
-		  .append(
-			";-------------------------------------\n"
-			"; CP WIPE TOWER FIRST LAYER BRIM START\n");
+	if (m_layer_change_in_layer == size_t(-1))
+		// First layer, prime the extruder.
+		return toolchange_Brim(tool);
 
-	// Move with Z hop and prime the extruder 10*perimeterWidth left along the vertical edge of the wipe tower.
-	writer.z_hop(zHop, 7200)
-		  .travel(wipeTower_box.lu - xy(perimeterWidth * 10.f, 0), 6000)
-		  .z_hop(0, 7200)
-		  .extrude_explicit(wipeTower_box.ld - xy(perimeterWidth * 10.f, 0), retract, 2400)
-		  .feedrate(2100);
-
-	if (sideOnly) {
-		float x_offset = 0.f;
-		for (size_t i = 0; i < 4; ++ i, x_offset += perimeterWidth)
-			writer.travel (wipeTower_box.ld + xy(- x_offset,   y_offset))
-				  .extrude(wipeTower_box.lu + xy(- x_offset, - y_offset));
-		writer.travel(wipeTower_box.rd + xy(x_offset, y_offset), 7000)
-			  .feedrate(2100);
-		x_offset = 0.f;
-		for (size_t i = 0; i < 4; ++ i, x_offset += perimeterWidth)
-			writer.travel (wipeTower_box.rd + xy(x_offset,   y_offset))
-				  .extrude(wipeTower_box.ru + xy(x_offset, - y_offset));
-	} else {
-		// Extrude 4 rounds of a brim around the future wipe tower.
-		box_coordinates box(wipeTower_box);
-		box.ld += xy(- perimeterWidth / 2, 0);
-		box.lu += xy(- perimeterWidth / 2, perimeterWidth);
-		box.rd += xy(  perimeterWidth / 2, 0);
-		box.ru += xy(  perimeterWidth / 2, perimeterWidth);
-		for (size_t i = 0; i < 4; ++ i) {
-			writer.travel(box.ld)
-				  .extrude(box.lu) .extrude(box.ru)
-				  .extrude(box.rd) .extrude(box.ld);
-			box.expand(perimeterWidth);
-		}
-	}
-
-	// Move to the front left corner and wipe along the front edge.
-	writer.travel(wipeTower_box.ld, 7000)
-		  .travel(wipeTower_box.rd)
-		  .travel(wipeTower_box.ld)
-		  .append("; CP WIPE TOWER FIRST LAYER BRIM END\n"
-			      ";-----------------------------------\n");
-
-	return writer.gcode();
-}
-
-std::pair<std::string, WipeTower::xy> WipeTower::Toolchange(
-	const int 			tool, 
-	const material_type current_material, 
-	const material_type new_material, 
-	const int 			temperature, 
-	const wipe_shape 	shape, 
-	const int 			count, 
-	const float 		spaceAvailable, 
-	const float 		wipeStartY, 
-	const bool  		lastInFile, 
-	const bool 			colorInit)
-{
 	box_coordinates cleaning_box(
 		m_wipe_tower_pos.x,
-		m_wipe_tower_pos.y + wipeStartY,
+		m_wipe_tower_pos.y + m_current_wipe_start_y,
 		m_wipe_tower_width, 
-		spaceAvailable - perimeterWidth / 2);
+		m_wipe_area - m_perimeter_width / 2);
 
-	Writer writer;
-	writer.set_extrusion_flow(extrusion_flow)
+	PrusaMultiMaterial::Writer writer;
+	writer.set_extrusion_flow(m_extrusion_flow)
 		  .set_z(m_z_pos)
 		  .append(";--------------------\n"
 			 	  "; CP TOOLCHANGE START\n")
-		  .comment_with_value(" toolchange #", count)
-		  .comment_material(current_material)
+		  .comment_with_value(" toolchange #", m_layer_change_total)
+		  .comment_material(m_current_material)
 		  .append(";--------------------\n")
 		  .speed_override(100)
 		  // Lift for a Z hop.
-		  .z_hop(zHop, 7200)
+		  .z_hop(m_zhop, 7200)
 		  // additional retract on move to tower
-		  .retract(retract/2, 3600)
-		  .travel(((shape == SHAPE_NORMAL) ? cleaning_box.ld : cleaning_box.rd) + xy(perimeterWidth, shape * perimeterWidth), 7200)
+		  .retract(m_retract/2, 3600)
+		  .travel(((m_current_shape == SHAPE_NORMAL) ? cleaning_box.ld : cleaning_box.rd) + xy(m_perimeter_width, m_current_shape * m_perimeter_width), 7200)
 		  // Unlift for a Z hop.
 		  .z_hop(0, 7200)
 		  // Additional retract on move to tower.
-		  .deretract(retract/2, 3600)
-		  .deretract(retract, 1500)
+		  .deretract(m_retract/2, 3600)
+		  .deretract(m_retract, 1500)
 		  // Increase extruder current for ramming.
 		  .set_extruder_trimpot(750)
 		  .flush_planner_queue();
 
 	// Ram the hot material out of the melt zone, retract the filament into the cooling tubes and let it cool.
-	toolchange_Unload(writer, cleaning_box, current_material, shape, temperature);
+	toolchange_Unload(writer, cleaning_box, m_current_material, m_current_shape, 
+		m_is_first_layer ? m_first_layer_temperature[tool]  : m_temperature[tool]);
 
-	if (! lastInFile) {
+	if (tool >= 0) {
+		// This is not the last change.
 		// Change the tool, set a speed override for solube and flex materials.
-		toolchange_Change(writer, tool, current_material, new_material);
-		toolchange_Load(writer, cleaning_box, current_material, shape, colorInit);
+		toolchange_Change(writer, tool, m_current_material, m_material[tool]);
+		toolchange_Load(writer, cleaning_box);
 		// Wipe the newly loaded filament until the end of the assigned wipe area.
-		toolchange_Wipe(writer, cleaning_box, current_material, shape);
+		toolchange_Wipe(writer, cleaning_box, m_current_material);
 		// Draw a perimeter around cleaning_box and wipe.
-		toolchange_Done(writer, cleaning_box, current_material, shape);
+		toolchange_Done(writer, cleaning_box);
 	}
 
 	// Reset the extruder current to a normal value.
@@ -387,20 +333,83 @@ std::pair<std::string, WipeTower::xy> WipeTower::Toolchange(
 	 		      ";------------------\n"
 				  "\n\n");
 
+    ++ m_layer_change_in_layer;
+    m_current_wipe_start_y += m_wipe_area;
+  	m_current_material = m_material[tool];
+	return std::pair<std::string, xy>(writer.gcode(), writer.pos());
+}
+
+std::pair<std::string, WipeTower::xy> WipeTowerPrusaMM::toolchange_Brim(size_t tool, bool sideOnly, float y_offset)
+{
+	const box_coordinates wipeTower_box(
+		m_wipe_tower_pos,
+		m_wipe_tower_width,
+		m_wipe_area * float(m_max_color_changes) - m_perimeter_width / 2);
+
+	PrusaMultiMaterial::Writer writer;
+	writer.set_extrusion_flow(m_extrusion_flow * 1.1f)
+		  // Let the writer know the current Z position as a base for Z-hop.
+		  .set_z(m_z_pos)
+		  .append(
+			";-------------------------------------\n"
+			"; CP WIPE TOWER FIRST LAYER BRIM START\n");
+
+	// Move with Z hop and prime the extruder 10*m_perimeter_width left along the vertical edge of the wipe tower.
+	writer.z_hop(m_zhop, 7200)
+		  .travel(wipeTower_box.lu - xy(m_perimeter_width * 10.f, 0), 6000)
+		  .z_hop(0, 7200)
+		  .extrude_explicit(wipeTower_box.ld - xy(m_perimeter_width * 10.f, 0), m_retract, 2400)
+		  .feedrate(2100);
+
+	toolchange_Change(writer, tool, m_current_material, m_material[tool]);
+
+	if (sideOnly) {
+		float x_offset = 0.f;
+		for (size_t i = 0; i < 4; ++ i, x_offset += m_perimeter_width)
+			writer.travel (wipeTower_box.ld + xy(- x_offset,   y_offset))
+				  .extrude(wipeTower_box.lu + xy(- x_offset, - y_offset));
+		writer.travel(wipeTower_box.rd + xy(x_offset, y_offset), 7000)
+			  .feedrate(2100);
+		x_offset = 0.f;
+		for (size_t i = 0; i < 4; ++ i, x_offset += m_perimeter_width)
+			writer.travel (wipeTower_box.rd + xy(x_offset,   y_offset))
+				  .extrude(wipeTower_box.ru + xy(x_offset, - y_offset));
+	} else {
+		// Extrude 4 rounds of a brim around the future wipe tower.
+		box_coordinates box(wipeTower_box);
+		box.ld += xy(- m_perimeter_width / 2, 0);
+		box.lu += xy(- m_perimeter_width / 2, m_perimeter_width);
+		box.rd += xy(  m_perimeter_width / 2, 0);
+		box.ru += xy(  m_perimeter_width / 2, m_perimeter_width);
+		for (size_t i = 0; i < 4; ++ i) {
+			writer.travel(box.ld)
+				  .extrude(box.lu) .extrude(box.ru)
+				  .extrude(box.rd) .extrude(box.ld);
+			box.expand(m_perimeter_width);
+		}
+	}
+
+	// Move to the front left corner and wipe along the front edge.
+	writer.travel(wipeTower_box.ld, 7000)
+		  .travel(wipeTower_box.rd)
+		  .travel(wipeTower_box.ld)
+		  .append("; CP WIPE TOWER FIRST LAYER BRIM END\n"
+			      ";-----------------------------------\n");
+
 	return std::pair<std::string, xy>(writer.gcode(), writer.pos());
 }
 
 // Ram the hot material out of the melt zone, retract the filament into the cooling tubes and let it cool.
-void WipeTower::toolchange_Unload(
-	Writer 				    &writer,
+void WipeTowerPrusaMM::toolchange_Unload(
+	PrusaMultiMaterial::Writer &writer,
 	const box_coordinates 	&cleaning_box,
 	const material_type		 material,
 	const wipe_shape 	     shape,
 	const int 				 temperature)
 {
-	float xl = cleaning_box.ld.x + (perimeterWidth / 2);
-	float xr = cleaning_box.rd.x - (perimeterWidth / 2);
-	float y_step = shape * perimeterWidth;
+	float xl = cleaning_box.ld.x + (m_perimeter_width / 2);
+	float xr = cleaning_box.rd.x - (m_perimeter_width / 2);
+	float y_step = shape * m_perimeter_width;
 
 	writer.append("; CP TOOLCHANGE UNLOAD");
 
@@ -409,20 +418,20 @@ void WipeTower::toolchange_Unload(
 	{
 	case PVA:
    		// ramming          start                    end                  y increment     amount feedrate
-		writer.ram(xl + perimeterWidth * 2, xr - perimeterWidth,     y_step * 1.2f, 3,     4000)
-			  .ram(xr - perimeterWidth,     xl + perimeterWidth,     y_step * 1.5f, 3,     4500)
-			  .ram(xl + perimeterWidth * 2, xr - perimeterWidth * 2, y_step * 1.5f, 3,     4800)
-			  .ram(xr - perimeterWidth,     xl + perimeterWidth,     y_step * 1.5f, 3,     5000);
+		writer.ram(xl + m_perimeter_width * 2, xr - m_perimeter_width,     y_step * 1.2f, 3,     4000)
+			  .ram(xr - m_perimeter_width,     xl + m_perimeter_width,     y_step * 1.5f, 3,     4500)
+			  .ram(xl + m_perimeter_width * 2, xr - m_perimeter_width * 2, y_step * 1.5f, 3,     4800)
+			  .ram(xr - m_perimeter_width,     xl + m_perimeter_width,     y_step * 1.5f, 3,     5000);
 		break;
 	case SCAFF:
-		writer.ram(xl + perimeterWidth * 2, xr - perimeterWidth,     y_step * 3.f,  3,     4000)
-			  .ram(xr - perimeterWidth,     xl + perimeterWidth,     y_step * 3.f,  4,     4600)
-			  .ram(xl + perimeterWidth * 2, xr - perimeterWidth * 2, y_step * 3.f,  4.5,   5200);
+		writer.ram(xl + m_perimeter_width * 2, xr - m_perimeter_width,     y_step * 3.f,  3,     4000)
+			  .ram(xr - m_perimeter_width,     xl + m_perimeter_width,     y_step * 3.f,  4,     4600)
+			  .ram(xl + m_perimeter_width * 2, xr - m_perimeter_width * 2, y_step * 3.f,  4.5,   5200);
 		break;
 	default:
-		writer.ram(xl + perimeterWidth * 2, xr - perimeterWidth,     y_step * 1.2f, 1.6f,  4000)
-			  .ram(xr - perimeterWidth,     xl + perimeterWidth,     y_step * 1.2f, 1.65f, 4600)
-			  .ram(xl + perimeterWidth * 2, xr - perimeterWidth * 2, y_step * 1.2f, 1.74f, 5200);
+		writer.ram(xl + m_perimeter_width * 2, xr - m_perimeter_width,     y_step * 1.2f, 1.6f,  4000)
+			  .ram(xr - m_perimeter_width,     xl + m_perimeter_width,     y_step * 1.2f, 1.65f, 4600)
+			  .ram(xl + m_perimeter_width * 2, xr - m_perimeter_width * 2, y_step * 1.2f, 1.74f, 5200);
 	}
 
 	// Pull the filament end into a cooling tube.
@@ -462,8 +471,8 @@ void WipeTower::toolchange_Unload(
 }
 
 // Change the tool, set a speed override for solube and flex materials.
-void WipeTower::toolchange_Change(
-	Writer 		   &writer,
+void WipeTowerPrusaMM::toolchange_Change(
+	PrusaMultiMaterial::Writer &writer,
 	const int 		tool, 
 	material_type  /* current_material */, 
 	material_type 	new_material)
@@ -481,15 +490,12 @@ void WipeTower::toolchange_Change(
 	      .flush_planner_queue();
 }
 
-void WipeTower::toolchange_Load(
-	Writer                 &writer,
-	const box_coordinates  &cleaning_box, 
-	const material_type 	/* material */,
-	const wipe_shape 		shape,
-	const bool 				colorInit)
+void WipeTowerPrusaMM::toolchange_Load(
+	PrusaMultiMaterial::Writer &writer,
+	const box_coordinates  &cleaning_box)
 {
-	float xl = cleaning_box.ld.x + perimeterWidth;
-	float xr = cleaning_box.rd.x - perimeterWidth;
+	float xl = cleaning_box.ld.x + m_perimeter_width;
+	float xr = cleaning_box.rd.x - m_perimeter_width;
 
 	writer.append("; CP TOOLCHANGE LOAD\n")
 	// Load the filament while moving left / right,
@@ -501,11 +507,12 @@ void WipeTower::toolchange_Load(
 
 	// Extrude first five lines (just three lines if colorInit is set).
 	writer.extrude(xr, writer.y(), 1600);
+	bool colorInit = false;
 	size_t pass = colorInit ? 1 : 2;
 	for (int i = 0; i < pass; ++ i)
-		writer.travel (xr, writer.y() + shape * perimeterWidth * 0.85f, 2200)
+		writer.travel (xr, writer.y() + m_current_shape * m_perimeter_width * 0.85f, 2200)
 			  .extrude(xl, writer.y())
-			  .travel (xl, writer.y() + shape * perimeterWidth * 0.85f)
+			  .travel (xl, writer.y() + m_current_shape * m_perimeter_width * 0.85f)
 			  .extrude(xr, writer.y());
 
 	// Reset the extruder current to the normal value.
@@ -513,52 +520,49 @@ void WipeTower::toolchange_Load(
 }
 
 // Wipe the newly loaded filament until the end of the assigned wipe area.
-void WipeTower::toolchange_Wipe(
-	Writer                 &writer,
+void WipeTowerPrusaMM::toolchange_Wipe(
+	PrusaMultiMaterial::Writer &writer,
 	const box_coordinates  &cleaning_box,
-	const material_type 	material,
-	const wipe_shape 	    shape)
+	const material_type 	material)
 {
 	// Increase flow on first layer, slow down print.
-	writer.set_extrusion_flow(extrusion_flow * (is_first_layer() ? 1.18f : 1.f))
+	writer.set_extrusion_flow(m_extrusion_flow * (m_is_first_layer ? 1.18f : 1.f))
 		  .append("; CP TOOLCHANGE WIPE\n");
-	float wipe_coeff = is_first_layer() ? 0.5f : 1.f;
-	float xl = cleaning_box.ld.x + 2.f * perimeterWidth;
-	float xr = cleaning_box.rd.x - 2.f * perimeterWidth;
+	float wipe_coeff = m_is_first_layer ? 0.5f : 1.f;
+	float xl = cleaning_box.ld.x + 2.f * m_perimeter_width;
+	float xr = cleaning_box.rd.x - 2.f * m_perimeter_width;
 	// Wipe speed will increase up to 4800.
 	float wipe_speed = 4200;
 	// Y increment per wipe line.
-	float dy = shape * perimeterWidth * 0.7f;
+	float dy = m_current_shape * m_perimeter_width * 0.7f;
 	for (bool p = true; ; p = ! p) {
 		writer.feedrate((wipe_speed = std::min(4800.f, wipe_speed + 50.f)) * wipe_coeff);
 		if (p)
-			writer.extrude(xl - perimeterWidth/2, writer.y() + dy)
-			      .extrude(xr + perimeterWidth,   writer.y());
+			writer.extrude(xl - m_perimeter_width/2, writer.y() + dy)
+			      .extrude(xr + m_perimeter_width,   writer.y());
 		else
-			writer.extrude(xl - perimeterWidth,   writer.y() + dy)
-				  .extrude(xr + perimeterWidth*2, writer.y());
+			writer.extrude(xl - m_perimeter_width,   writer.y() + dy)
+				  .extrude(xr + m_perimeter_width*2, writer.y());
 		writer.feedrate((wipe_speed = std::min(4800.f, wipe_speed + 50.f)) * wipe_coeff)
-			  .extrude(xr + perimeterWidth, writer.y() + dy)
-			  .extrude(xl - perimeterWidth, writer.y());
-		if ((shape == SHAPE_NORMAL) ?
-			(writer.y() > cleaning_box.lu.y - perimeterWidth) :
-			(writer.y() < cleaning_box.ld.y + perimeterWidth))
+			  .extrude(xr + m_perimeter_width, writer.y() + dy)
+			  .extrude(xl - m_perimeter_width, writer.y());
+		if ((m_current_shape == SHAPE_NORMAL) ?
+			(writer.y() > cleaning_box.lu.y - m_perimeter_width) :
+			(writer.y() < cleaning_box.ld.y + m_perimeter_width))
 			// Next wipe line does not fit the cleaning box.
 			break;
 	}
 	// Reset the extrusion flow.
-	writer.set_extrusion_flow(extrusion_flow);
+	writer.set_extrusion_flow(m_extrusion_flow);
 }
 
 // Draw a perimeter around cleaning_box and wipe.
-void WipeTower::toolchange_Done(
-	Writer 					&writer,
-	const box_coordinates 	&cleaning_box,
-	const material_type 	/* material */, 
-	const wipe_shape 		 shape)
+void WipeTowerPrusaMM::toolchange_Done(
+	PrusaMultiMaterial::Writer &writer,
+	const box_coordinates 	&cleaning_box)
 {
 	box_coordinates box = cleaning_box;
-	if (shape == SHAPE_REVERSED) {
+	if (m_current_shape == SHAPE_REVERSED) {
 		std::swap(box.lu, box.ld);
 		std::swap(box.ru, box.rd);
 	}
@@ -572,82 +576,86 @@ void WipeTower::toolchange_Done(
 		  .feedrate(6000);
 }
 
-std::string WipeTower::Perimeter(int order, int total, int Layer, bool afterToolchange, int firstLayerOffset)
+std::pair<std::string, WipeTower::xy> WipeTowerPrusaMM::close_layer()
 {
-	Writer writer;
-	writer.set_extrusion_flow(extrusion_flow)
+	PrusaMultiMaterial::Writer writer;
+	writer.set_extrusion_flow(m_extrusion_flow)
 		  .set_z(m_z_pos)
 		  .append(";--------------------\n"
 				  "; CP EMPTY GRID START\n")
-		  .comment_with_value(" layer #", Layer);
+		  .comment_with_value(" layer #", m_layer_change_total ++);
 
 	// Slow down on the 1st layer.
-	float speed_factor = is_first_layer() ? 0.5f : 1.f;
+	float speed_factor = m_is_first_layer ? 0.5f : 1.f;
 
-	box_coordinates _p  = _boxForColor(order);
+	box_coordinates _p  = _boxForColor(m_layer_change_in_layer);
 	{
-		box_coordinates _to = _boxForColor(total);
+		box_coordinates _to = _boxForColor(m_max_color_changes);
+		float firstLayerOffset = 0.f;
 		_p.ld.y += firstLayerOffset;
 		_p.rd.y += firstLayerOffset;
 		_p.lu = _to.lu; _p.ru = _to.ru;
 	}
 
-	if (! afterToolchange)
+	if (m_layer_change_in_layer == 0)
+		// There were no tool changes at all in this layer.
 		// Jump with retract to _p.ld + a random shift in +x.
-		writer.retract(retract * 1.5f, 3600)
-			  .z_hop(zHop, 7200)
+		writer.retract(m_retract * 1.5f, 3600)
+			  .z_hop(m_zhop, 7200)
 			  .travel(_p.ld.x + randi(5, 20), _p.ld.y, 7000)
 			  .z_hop(0, 7200)
-			  .extrude_explicit(_p.ld, retract * 1.5f, 3600);
+			  .extrude_explicit(_p.ld, m_retract * 1.5f, 3600);
 
 	box_coordinates box = _p;
 	writer.extrude(box.lu, 2400 * speed_factor)
 		  .extrude(box.ru)
 		  .extrude(box.rd)
-		  .extrude(box.ld + xy(perimeterWidth / 2, 0));
+		  .extrude(box.ld + xy(m_perimeter_width / 2, 0));
 
-	box.expand(- perimeterWidth / 2);
+	box.expand(- m_perimeter_width / 2);
 	writer.extrude(box.lu, 3200 * speed_factor)
 		  .extrude(box.ru)
 		  .extrude(box.rd)
-		  .extrude(box.ld + xy(perimeterWidth / 2, 0))
-		  .extrude(box.ld + xy(perimeterWidth / 2, perimeterWidth / 2));
+		  .extrude(box.ld + xy(m_perimeter_width / 2, 0))
+		  .extrude(box.ld + xy(m_perimeter_width / 2, m_perimeter_width / 2));
 
-	writer.extrude(_p.ld + xy(perimeterWidth * 3,   perimeterWidth), 2900 * speed_factor)
-	      .extrude(_p.lu + xy(perimeterWidth * 3, - perimeterWidth))
-		  .extrude(_p.lu + xy(perimeterWidth * 6, - perimeterWidth))
-		  .extrude(_p.ld + xy(perimeterWidth * 6,   perimeterWidth));
+	writer.extrude(_p.ld + xy(m_perimeter_width * 3,   m_perimeter_width), 2900 * speed_factor)
+	      .extrude(_p.lu + xy(m_perimeter_width * 3, - m_perimeter_width))
+		  .extrude(_p.lu + xy(m_perimeter_width * 6, - m_perimeter_width))
+		  .extrude(_p.ld + xy(m_perimeter_width * 6,   m_perimeter_width));
 
 	if (_p.lu.y - _p.ld.y > 4) {
 		// Extrude three zig-zags.
 		writer.feedrate(3200 * speed_factor);
-		float step = (m_wipe_tower_width - perimeterWidth * 12.f) / 12.f;
+		float step = (m_wipe_tower_width - m_perimeter_width * 12.f) / 12.f;
 		for (size_t i = 0; i < 3; ++ i) {
-			writer.extrude(writer.x() + step, _p.ld.y + perimeterWidth * 8);
-			writer.extrude(writer.x()       , _p.lu.y - perimeterWidth * 8);
-			writer.extrude(writer.x() + step, _p.lu.y - perimeterWidth    );
-			writer.extrude(writer.x() + step, _p.lu.y - perimeterWidth * 8);
-			writer.extrude(writer.x()       , _p.ld.y + perimeterWidth * 8);
-			writer.extrude(writer.x() + step, _p.ld.y + perimeterWidth    );
+			writer.extrude(writer.x() + step, _p.ld.y + m_perimeter_width * 8);
+			writer.extrude(writer.x()       , _p.lu.y - m_perimeter_width * 8);
+			writer.extrude(writer.x() + step, _p.lu.y - m_perimeter_width    );
+			writer.extrude(writer.x() + step, _p.lu.y - m_perimeter_width * 8);
+			writer.extrude(writer.x()       , _p.ld.y + m_perimeter_width * 8);
+			writer.extrude(writer.x() + step, _p.ld.y + m_perimeter_width    );
 		}
 	}
 
-	writer.extrude(_p.ru + xy(- perimeterWidth * 6, - perimeterWidth), 2900 * speed_factor)
-		  .extrude(_p.ru + xy(- perimeterWidth * 3, - perimeterWidth))
-		  .extrude(_p.rd + xy(- perimeterWidth * 3,   perimeterWidth))
-		  .extrude(_p.rd + xy(- perimeterWidth,       perimeterWidth))
+	// Extrude the perimeter.
+	writer.extrude(_p.ru + xy(- m_perimeter_width * 6, - m_perimeter_width), 2900 * speed_factor)
+		  .extrude(_p.ru + xy(- m_perimeter_width * 3, - m_perimeter_width))
+		  .extrude(_p.rd + xy(- m_perimeter_width * 3,   m_perimeter_width))
+		  .extrude(_p.rd + xy(- m_perimeter_width,       m_perimeter_width))
        	  // Wipe along the front side of the current wiping box.
-		  .travel(_p.ld + xy(  perimeterWidth, perimeterWidth / 2), 7200)
-		  .travel(_p.rd + xy(- perimeterWidth, perimeterWidth / 2))
+		  .travel(_p.ld + xy(  m_perimeter_width, m_perimeter_width / 2), 7200)
+		  .travel(_p.rd + xy(- m_perimeter_width, m_perimeter_width / 2))
 		  .append("; CP EMPTY GRID END\n"
 			      ";------------------\n\n\n\n\n\n\n");
 
-	return writer.gcode();
+	m_current_shape = wipe_shape(- m_current_shape);
+	return std::pair<std::string, xy>(writer.gcode(), writer.pos());
 }
 
-WipeTower::box_coordinates WipeTower::_boxForColor(int order) const
+WipeTowerPrusaMM::box_coordinates WipeTowerPrusaMM::_boxForColor(int order) const
 {
-	return box_coordinates(m_wipe_tower_pos.x, m_wipe_tower_pos.y + m_wipe_area * order - perimeterWidth / 2, m_wipe_tower_width, perimeterWidth);
+	return box_coordinates(m_wipe_tower_pos.x, m_wipe_tower_pos.y + m_wipe_area * order - m_perimeter_width / 2, m_wipe_tower_width, m_perimeter_width);
 }
 
-}; // namespace PrusaSingleExtruderMM
+}; // namespace Slic3r
diff --git a/xs/src/libslic3r/GCode/WipeTowerPrusaMM.hpp b/xs/src/libslic3r/GCode/WipeTowerPrusaMM.hpp
new file mode 100644
index 0000000000..6e804a725e
--- /dev/null
+++ b/xs/src/libslic3r/GCode/WipeTowerPrusaMM.hpp
@@ -0,0 +1,217 @@
+#ifndef WipeTowerPrusaMM_hpp_
+#define WipeTowerPrusaMM_hpp_
+
+#include <algorithm>
+#include <string>
+#include <utility>
+
+#include "WipeTower.hpp"
+
+namespace Slic3r
+{
+
+namespace PrusaMultiMaterial {
+	class Writer;
+};
+
+class WipeTowerPrusaMM : public WipeTower
+{
+public:
+	enum material_type
+	{
+		INVALID = -1,
+		PLA   = 0,		// E:210C	B:55C
+		ABS   = 1,		// E:255C	B:100C
+		PET   = 2,		// E:240C	B:90C
+		HIPS  = 3,		// E:220C	B:100C
+		FLEX  = 4,		// E:245C	B:80C
+		SCAFF = 5,		// E:215C	B:55C
+		EDGE  = 6,		// E:240C	B:80C
+		NGEN  = 7,		// E:230C	B:80C
+		PVA   = 8	    // E:210C	B:80C
+	};
+
+	// Parse material name into material_type.
+	static material_type parse_material(const char *name);
+
+	// x			-- x coordinates of wipe tower in mm ( left bottom corner )
+	// y			-- y coordinates of wipe tower in mm ( left bottom corner )
+	// width		-- width of wipe tower in mm ( default 60 mm - leave as it is )
+	// wipe_area	-- space available for one toolchange in mm
+	WipeTowerPrusaMM(float x, float y, float width, float wipe_area) :
+		m_wipe_tower_pos(x, y),
+		m_wipe_tower_width(width),
+		m_wipe_area(wipe_area),
+		m_z_pos(0.f) {
+		for (size_t i = 0; i < 4; ++ i) {
+			// Extruder specific parameters.
+			m_material[i] = PLA;
+			m_temperature[i] = 0;
+			m_first_layer_temperature[i] = 0;
+		}
+	}
+	virtual ~WipeTowerPrusaMM() {}
+
+	// _retract - retract value in mm
+	void set_retract(float retract) { m_retract = retract; }
+	
+	// _zHop - z hop value in mm
+	void set_zhop(float zhop) { m_zhop = zhop; }
+
+	// Set the extruder properties.
+	void set_extruder(size_t idx, material_type material, int temp, int first_layer_temp)
+	{
+		m_material[idx] = material;
+		m_temperature[idx] = temp;
+		m_first_layer_temperature[idx] = first_layer_temp;
+	}
+
+	// Switch to a next layer.
+	virtual void set_layer(
+		// Print height of this layer.
+		float  print_z,
+		// Layer height, used to calculate extrusion the rate. 
+		float  layer_height, 
+		// Maximum number of tool changes on this layer or the layers below.
+		size_t max_tool_changes, 
+		// Is this the first layer of the print? In that case print the brim first.
+		bool   is_first_layer,
+		// Is this the last layer of the waste tower?
+		bool   is_last_layer)
+	{
+		m_z_pos 				= print_z;
+		m_max_color_changes 	= max_tool_changes;
+		m_is_first_layer 		= is_first_layer;
+		m_is_last_layer			= is_last_layer;
+		// Start counting the color changes from zero.
+		m_layer_change_in_layer = is_first_layer ? size_t(-1) : 0;
+		m_current_wipe_start_y  = 0.f;
+
+		int layer_idx = int(floor(layer_height * 100) + 0.5f);
+		switch (layer_idx)
+		{
+		case 15:
+			m_extrusion_flow = (float)0.024;
+			break;
+		case 20:
+		default:
+			m_extrusion_flow = (float)0.029;
+			break;
+		}
+	}
+
+	// Return the wipe tower position.
+	virtual const xy& position() const { return m_wipe_tower_pos; }
+	// The wipe tower is finished, there should be no more tool changes or wipe tower prints.
+	virtual bool 	  finished() const { return m_max_color_changes == 0; }
+
+	// Returns gcode for toolchange 
+	virtual std::pair<std::string, xy> tool_change(int new_tool);
+
+	// Close the current wipe tower layer with a perimeter and possibly fill the unfilled space with a zig-zag.
+	virtual std::pair<std::string, xy> close_layer();
+
+private:
+	WipeTowerPrusaMM();
+
+	enum wipe_shape
+	{
+		SHAPE_NORMAL   = 1,
+		SHAPE_REVERSED = -1
+	};
+
+	// Left front corner of the wipe tower in mm.
+	xy     m_wipe_tower_pos;
+	// Width of the wipe tower.
+	float  m_wipe_tower_width;
+	// Per color Y span.
+	float  m_wipe_area;
+	// Current Z position.
+	float  m_z_pos 			= 0.f;
+	// Maximum number of color changes per layer.
+	size_t m_max_color_changes = 0;
+	// Is this the 1st layer of the print? If so, print the brim around the waste tower.
+	bool   m_is_first_layer = false;
+	// Is this the last layer of this waste tower?
+	bool   m_is_last_layer  = false;
+
+	// G-code generator parameters.
+	float  m_zhop 			 = 0.5f;
+	float  m_retract		 = 4.f;
+	float  m_perimeter_width = 0.5f;
+	float  m_extrusion_flow  = 0.029f;
+
+	// Extruder specific parameters.
+	material_type 	m_material[4];
+	int  			m_temperature[4];
+	int  			m_first_layer_temperature[4];
+
+	// State of the wiper tower generator.
+	// Layer change counter for the output statistics.
+	unsigned int 	m_layer_change_total = 0;
+	// Layer change counter in this layer. Counting up to m_max_color_changes.
+	unsigned int 	m_layer_change_in_layer = 0;
+	wipe_shape   	m_current_shape = SHAPE_NORMAL;
+	material_type 	m_current_material = PLA;
+	// Current y position at the wipe tower.
+	float 		 	m_current_wipe_start_y = 0.f;
+
+	struct box_coordinates
+	{
+		box_coordinates(float left, float bottom, float width, float height) :
+			ld(left        , bottom         ),
+			lu(left        , bottom + height),
+			rd(left + width, bottom         ),
+			ru(left + width, bottom + height) {}
+		box_coordinates(const xy &pos, float width, float height) : box_coordinates(pos.x, pos.y, width, height) {}
+		void expand(const float offset) {
+			ld += xy(- offset, - offset);
+			lu += xy(- offset,   offset);
+			rd += xy(  offset, - offset);
+			ru += xy(  offset,   offset);
+		}
+		xy ld;  // left down
+		xy lu;	// left upper 
+		xy ru;	// right upper
+		xy rd;	// right lower
+	};
+
+	// Returns gcode for wipe tower brim
+	// sideOnly			-- set to false -- experimental, draw brim on sides of wipe tower 
+	// offset			-- set to 0		-- experimental, offset to replace brim in front / rear of wipe tower
+	std::pair<std::string, WipeTower::xy> toolchange_Brim(size_t tool, bool sideOnly = false, float y_offset = 0.f);
+
+	void toolchange_Unload(
+		PrusaMultiMaterial::Writer &writer,
+		const box_coordinates  &cleaning_box, 
+		const material_type	 	material,
+		const wipe_shape 	    shape,
+		const int 				temperature);
+
+	void toolchange_Change(
+		PrusaMultiMaterial::Writer &writer,
+		int 					tool,
+		material_type 			current_material,
+		material_type 			new_material);
+	
+	void toolchange_Load(
+		PrusaMultiMaterial::Writer &writer,
+		const box_coordinates  &cleaning_box);
+	
+	void toolchange_Wipe(
+		PrusaMultiMaterial::Writer &writer,
+		const box_coordinates  &cleaning_box, 
+		const material_type 	material);
+	
+	void toolchange_Done(
+		PrusaMultiMaterial::Writer &writer,
+		const box_coordinates  &cleaning_box);
+
+	void toolchange_Perimeter();
+
+	box_coordinates _boxForColor(int order) const;
+};
+
+}; // namespace Slic3r
+
+#endif /* WipeTowerPrusaMM_hpp_ */
diff --git a/xs/src/libslic3r/PrintConfig.cpp b/xs/src/libslic3r/PrintConfig.cpp
index b73390ab1f..a7b88c9928 100644
--- a/xs/src/libslic3r/PrintConfig.cpp
+++ b/xs/src/libslic3r/PrintConfig.cpp
@@ -354,6 +354,37 @@ PrintConfigDef::PrintConfigDef()
         def->default_value = opt;
     }
 
+    def = this->add("filament_type", coStrings);
+    def->label = "Filament type";
+    def->tooltip = "If you want to process the output G-code through custom scripts, just list their absolute paths here. Separate multiple scripts with a semicolon. Scripts will be passed the absolute path to the G-code file as the first argument, and they can access the Slic3r config settings by reading environment variables.";
+    def->cli = "filament_type=s@";
+    def->gui_type = "f_enum_open";
+    def->gui_flags = "show_value";
+    def->enum_values.push_back("PLA");
+    def->enum_values.push_back("ABS");
+    def->enum_values.push_back("PET");
+    def->enum_values.push_back("HIPS");
+    def->enum_values.push_back("FLEX");
+    def->enum_values.push_back("SCAFF");
+    def->enum_values.push_back("EDGE");
+    def->enum_values.push_back("NGEN");
+    def->enum_values.push_back("PVA");
+    {
+        ConfigOptionStrings* opt = new ConfigOptionStrings();
+        opt->values.push_back("PLA");
+        def->default_value = opt;
+    }
+
+    def = this->add("filament_soluble", coBools);
+    def->label = "Soluble material";
+    def->tooltip = "Soluble material is most likely used for a soluble support.";
+    def->cli = "filament-soluble!";
+    {
+        ConfigOptionBools* opt = new ConfigOptionBools();
+        opt->values.push_back(false);
+        def->default_value = opt;
+    }
+
     def = this->add("filament_cost", coFloats);
     def->label = "Cost";
     def->tooltip = "Enter your filament cost per kg here. This is only for statistical information.";
@@ -1168,6 +1199,12 @@ PrintConfigDef::PrintConfigDef()
     def->height = 120;
     def->default_value = new ConfigOptionString("G28 ; home all axes\nG1 Z5 F5000 ; lift nozzle\n");
 
+    def = this->add("single_extruder_multi_material", coBool);
+    def->label = "Single Extruder Multi Material";
+    def->tooltip = "The printer multiplexes filaments into a single hot end.";
+    def->cli = "single-extruder-multi-material!";
+    def->default_value = new ConfigOptionBool(false);
+
     def = this->add("support_material", coBool);
     def->label = "Generate support material";
     def->category = "Support material";
@@ -1454,6 +1491,40 @@ PrintConfigDef::PrintConfigDef()
         def->default_value = opt;
     }
 
+    def = this->add("wipe_tower", coBool);
+    def->label = "Enable";
+    def->tooltip = "Multi material printers may need to prime or purge extruders on tool changes. Extrude the excess material into the wipe tower.";
+    def->cli = "wipe-tower!";
+    def->default_value = new ConfigOptionBool(false);
+
+    def = this->add("wipe_tower_x", coFloat);
+    def->label = "Position X";
+    def->tooltip = "X coordinate of the left front corner of a wipe tower";
+    def->sidetext = "mm";
+    def->cli = "wipe-tower-x=f";
+    def->default_value = new ConfigOptionFloat(180.);
+
+    def = this->add("wipe_tower_y", coFloat);
+    def->label = "Position Y";
+    def->tooltip = "Y coordinate of the left front corner of a wipe tower";
+    def->sidetext = "mm";
+    def->cli = "wipe-tower-y=f";
+    def->default_value = new ConfigOptionFloat(140.);
+
+    def = this->add("wipe_tower_width", coFloat);
+    def->label = "Width";
+    def->tooltip = "Width of a wipe tower";
+    def->sidetext = "mm";
+    def->cli = "wipe-tower-width=f";
+    def->default_value = new ConfigOptionFloat(60.);
+
+    def = this->add("wipe_tower_per_color_wipe", coFloat);
+    def->label = "Per color change depth";
+    def->tooltip = "Depth of a wipe color per color change. For N colors, there will be maximum (N-1) tool switches performed, therefore the total depth of the wipe tower will be (N-1) times this value.";
+    def->sidetext = "mm";
+    def->cli = "wipe-tower-per-color-wipe=f";
+    def->default_value = new ConfigOptionFloat(15.);
+
     def = this->add("xy_size_compensation", coFloat);
     def->label = "XY Size Compensation";
     def->category = "Advanced";
diff --git a/xs/src/libslic3r/PrintConfig.hpp b/xs/src/libslic3r/PrintConfig.hpp
index 770d2664dd..7a826d7e8f 100644
--- a/xs/src/libslic3r/PrintConfig.hpp
+++ b/xs/src/libslic3r/PrintConfig.hpp
@@ -42,6 +42,10 @@ enum SeamPosition {
     spRandom, spNearest, spAligned, spRear
 };
 
+enum FilamentType {
+    ftPLA, ftABS, ftPET, ftHIPS, ftFLEX, ftSCAFF, ftEDGE, ftNGEN, ftPVA
+};
+
 template<> inline t_config_enum_values ConfigOptionEnum<GCodeFlavor>::get_enum_values() {
     t_config_enum_values keys_map;
     keys_map["reprap"]          = gcfRepRap;
@@ -91,6 +95,20 @@ template<> inline t_config_enum_values ConfigOptionEnum<SeamPosition>::get_enum_
     return keys_map;
 }
 
+template<> inline t_config_enum_values ConfigOptionEnum<FilamentType>::get_enum_values() {
+    t_config_enum_values keys_map;
+    keys_map["PLA"]             = ftPLA;
+    keys_map["ABS"]             = ftABS;
+    keys_map["PET"]             = ftPET;
+    keys_map["HIPS"]            = ftHIPS;
+    keys_map["FLEX"]            = ftFLEX;
+    keys_map["SCAFF"]           = ftSCAFF;
+    keys_map["EDGE"]            = ftEDGE;
+    keys_map["NGEN"]            = ftNGEN;
+    keys_map["PVA"]             = ftPVA;
+    return keys_map;
+}
+
 // Defines each and every confiuration option of Slic3r, including the properties of the GUI dialogs.
 // Does not store the actual values, but defines default values.
 class PrintConfigDef : public ConfigDef
@@ -297,13 +315,15 @@ class PrintRegionConfig : public virtual StaticPrintConfig
 // This object is mapped to Perl as Slic3r::Config::GCode.
 class GCodeConfig : public virtual StaticPrintConfig
 {
-    public:
+public:
     ConfigOptionString              before_layer_gcode;
     ConfigOptionString              end_gcode;
     ConfigOptionString              extrusion_axis;
     ConfigOptionFloats              extrusion_multiplier;
     ConfigOptionFloats              filament_diameter;
     ConfigOptionFloats              filament_density;
+    ConfigOptionStrings             filament_type;
+    ConfigOptionBools               filament_soluble;
     ConfigOptionFloats              filament_cost;
     ConfigOptionFloats              filament_max_volumetric_speed;
     ConfigOptionBool                gcode_comments;
@@ -322,6 +342,7 @@ class GCodeConfig : public virtual StaticPrintConfig
     ConfigOptionFloats              retract_restart_extra_toolchange;
     ConfigOptionFloats              retract_speed;
     ConfigOptionString              start_gcode;
+    ConfigOptionBool                single_extruder_multi_material;
     ConfigOptionString              toolchange_gcode;
     ConfigOptionFloat               travel_speed;
     ConfigOptionBool                use_firmware_retraction;
@@ -341,6 +362,8 @@ class GCodeConfig : public virtual StaticPrintConfig
         OPT_PTR(extrusion_multiplier);
         OPT_PTR(filament_diameter);
         OPT_PTR(filament_density);
+        OPT_PTR(filament_type);
+        OPT_PTR(filament_soluble);
         OPT_PTR(filament_cost);
         OPT_PTR(filament_max_volumetric_speed);
         OPT_PTR(gcode_comments);
@@ -358,6 +381,7 @@ class GCodeConfig : public virtual StaticPrintConfig
         OPT_PTR(retract_restart_extra);
         OPT_PTR(retract_restart_extra_toolchange);
         OPT_PTR(retract_speed);
+        OPT_PTR(single_extruder_multi_material);
         OPT_PTR(start_gcode);
         OPT_PTR(toolchange_gcode);
         OPT_PTR(travel_speed);
@@ -435,6 +459,11 @@ class PrintConfig : public GCodeConfig
     ConfigOptionInts                temperature;
     ConfigOptionInt                 threads;
     ConfigOptionBools               wipe;
+    ConfigOptionBool                wipe_tower;
+    ConfigOptionFloat               wipe_tower_x;
+    ConfigOptionFloat               wipe_tower_y;
+    ConfigOptionFloat               wipe_tower_width;
+    ConfigOptionFloat               wipe_tower_per_color_wipe;
     ConfigOptionFloat               z_offset;
     
     PrintConfig(bool initialize = true) : GCodeConfig(false) {
@@ -494,6 +523,11 @@ class PrintConfig : public GCodeConfig
         OPT_PTR(temperature);
         OPT_PTR(threads);
         OPT_PTR(wipe);
+        OPT_PTR(wipe_tower);
+        OPT_PTR(wipe_tower_x);
+        OPT_PTR(wipe_tower_y);
+        OPT_PTR(wipe_tower_width);
+        OPT_PTR(wipe_tower_per_color_wipe);
         OPT_PTR(z_offset);
         
         // look in parent class
diff --git a/xs/src/libslic3r/WipeTower.hpp b/xs/src/libslic3r/WipeTower.hpp
deleted file mode 100644
index 38d8203c95..0000000000
--- a/xs/src/libslic3r/WipeTower.hpp
+++ /dev/null
@@ -1,210 +0,0 @@
-#ifndef PrusaSingleExtruderMM_WipeTower_hpp_
-#define PrusaSingleExtruderMM_WipeTower_hpp_
-
-#include <algorithm>
-#include <string>
-#include <utility>
-
-namespace PrusaSingleExtruderMM
-{
-
-class Writer;
-
-class WipeTower
-{
-public:
-	enum material_type
-	{
-		INVALID = -1,
-		PLA   = 0,		// E:210C	B:55C
-		ABS   = 1,		// E:255C	B:100C
-		PET   = 2,		// E:240C	B:90C
-		HIPS  = 3,		// E:220C	B:100C
-		FLEX  = 4,		// E:245C	B:80C
-		SCAFF = 5,		// E:215C	B:55C
-		EDGE  = 6,		// E:240C	B:80C
-		NGEN  = 7,		// E:230C	B:80C
-		PVA   = 8	    // E:210C	B:80C
-	};
-
-	enum wipe_shape
-	{
-		SHAPE_NORMAL   = 1,
-		SHAPE_REVERSED = -1
-	};
-
-	struct xy
-	{
-		xy(float x = 0.f, float y = 0.f) : x(x), y(y) {}
-		xy  operator+(const xy &rhs) const { xy out(*this); out.x += rhs.x; out.y += rhs.y; return out; }
-		xy  operator-(const xy &rhs) const { xy out(*this); out.x -= rhs.x; out.y -= rhs.y; return out; }
-		xy& operator+=(const xy &rhs) { x += rhs.x; y += rhs.y; return *this; }
-		xy& operator-=(const xy &rhs) { x -= rhs.x; y -= rhs.y; return *this; }
-		float x;
-		float y;
-	};
-
-	// Parse material name into material_type.
-	static material_type parse_material(const char *name);
-
-	// x			-- x coordinates of wipe tower in mm ( left bottom corner )
-	// y			-- y coordinates of wipe tower in mm ( left bottom corner )
-	// width		-- width of wipe tower in mm ( default 60 mm - leave as it is )
-	// wipe_area	-- space available for one toolchange in mm
-	// colors		-- maximum colors for object
-	WipeTower(float x, float y, float width, float wipe_area, int color_changes) :
-		m_wipe_tower_pos(x, y),
-		m_wipe_tower_width(width),
-		m_wipe_area(wipe_area),
-		m_color_changes(color_changes),
-		m_z_pos(0.f) {}
-
-	// colors		-- maximum color changes for layer
-	void setColors(int colors) { m_color_changes = colors; }
-
-	// Z height		-- mm
-	void setZ(float z) { m_z_pos = z; }
-	bool is_first_layer() const { return m_z_pos < 0.205f; }
-
-	// _retract - retract value in mm
-	void setRetract(float _retract) { retract = _retract; }
-	
-	// _zHop - z hop value in mm
-	void setZHop(float _zhop) { zHop = _zhop; }
-
-	void setExtrusion(int layerHeight)
-	{
-		// set extrusion coefficient for layer height 
-		// layerHeight		-- mm * 100
-
-		switch (layerHeight)
-		{
-		case 15:
-			extrusion_flow = (float)0.024;
-			break;
-		case 20:
-			extrusion_flow = (float)0.029;
-			break;
-		default:
-			break;
-		}
-	}
-
-	/*
-		Returns gcode for wipe tower brim
-	
-		sideOnly			-- set to false -- experimental, draw brim on sides of wipe tower 
-		offset				-- set to 0		-- experimental, offset to replace brim in front / rear of wipe tower
-	*/
-	std::string FirstLayer(bool sideOnly = false, float y_offset = 0.f);
-
-	// Returns gcode for toolchange 
-	std::pair<std::string, WipeTower::xy> Toolchange(
-		// extruder #   0 - 3
-		const int 			tool, 
-		// filament type currently used to print and loaded in nozzle -- see enum material_type
-		const material_type current_material, 
-		// filament type that will be loaded in to the nozzle  -- see enum material_type
-		const material_type new_material, 
-		// temperature in Celsius for new filament that will be loaded into the nozzle	
-		const int 			temperature, 
-		// orientation of purge / wipe shape (NORMAL / REVERSED)
-		const wipe_shape 	shape, 
-		// total toolchanges done counter ( comment in  header of toolchange only )
-		const int 			count, 
-		// space available for toolchange ( purge / load / wipe ) - in mm
-		const float 		spaceAvailable, 
-		// experimental, don't use, set to 0
-		const float 		wipeStartY, 
-		// for last toolchange in object set to true to unload filament into cooling tube, for all other set to false
-		const bool  		lastInFile, 
-		// experimental, set to false
-		const bool 			colorInit = false);
-
-	/*
-		Returns gcode to draw empty pattern in place of a toolchange -> in case there are less toolchanges atm then what is required later 
-
-		order				-- total toolchanges done for current layer
-		total				-- total colors in current z layer including empty ones
-		afterToolchange		-- true - ignore some not neccesary moves | false - do whole move from object to wipe tower
-		firstLayerOffset	-- experimental , set to 0
-	*/
-	std::string Perimeter(int order, int total, int Layer, bool afterToolchange, int firstLayerOffset = 0);
-
-private:
-	WipeTower();
-
-	// Left front corner of the wipe tower in mm.
-	xy    m_wipe_tower_pos;
-	// Width of the wipe tower.
-	float m_wipe_tower_width;
-	// Per color Y span.
-	float m_wipe_area;
-	// Current Z position.
-	float m_z_pos;
-	// Maximum number of color changes per layer.
-	int   m_color_changes;
-
-	float zHop 				= 0.5f;
-	float retract 			= 4.f;
-	float perimeterWidth 	= 0.5f;
-	float extrusion_flow 	= 0.029f;
-
-	struct box_coordinates
-	{
-		box_coordinates(float left, float bottom, float width, float height) :
-			ld(left        , bottom         ),
-			lu(left        , bottom + height),
-			rd(left + width, bottom         ),
-			ru(left + width, bottom + height) {}
-		box_coordinates(const xy &pos, float width, float height) : box_coordinates(pos.x, pos.y, width, height) {}
-		void expand(const float offset) {
-			ld += xy(- offset, - offset);
-			lu += xy(- offset,   offset);
-			rd += xy(  offset, - offset);
-			ru += xy(  offset,   offset);
-		}
-		xy ld;  // left down
-		xy lu;	// left upper 
-		xy ru;	// right upper
-		xy rd;	// right lower
-	};
-	
-	void toolchange_Unload(
-		Writer				   &writer,
-		const box_coordinates  &cleaning_box, 
-		const material_type	 	material,
-		const wipe_shape 	    shape,
-		const int 				temperature);
-
-	void toolchange_Change(
-		Writer				   &writer,
-		int 					tool,
-		material_type 			current_material,
-		material_type 			new_material);
-	
-	void toolchange_Load(
-		Writer				   &writer,
-		const box_coordinates  &cleaning_box,
-		const material_type 	material,
-		const wipe_shape 		shape,
-		const bool 				colorInit);
-	
-	void toolchange_Wipe(
-		Writer				   &writer,
-		const box_coordinates  &cleaning_box, 
-		const material_type 	material,
-		const wipe_shape 	    shape);
-	
-	void toolchange_Done(
-		Writer				   &writer,
-		const box_coordinates  &cleaning_box, 
-		const material_type 	material, 
-		const wipe_shape 		shape);
-
-	box_coordinates _boxForColor(int order) const;
-};
-
-}; // namespace PrusaSingleExtruderMM
-
-#endif /* PrusaSingleExtruderMM_WipeTower_hpp_ */