diff --git a/lib/Slic3r.pm b/lib/Slic3r.pm
index 7ba801bf4..ee53fd461 100644
--- a/lib/Slic3r.pm
+++ b/lib/Slic3r.pm
@@ -68,7 +68,6 @@ use Slic3r::Polygon;
 use Slic3r::Polyline;
 use Slic3r::Print;
 use Slic3r::Print::Object;
-use Slic3r::Print::Region;
 use Slic3r::Print::Simple;
 use Slic3r::Print::SupportMaterial;
 use Slic3r::Surface;
diff --git a/lib/Slic3r/Fill.pm b/lib/Slic3r/Fill.pm
index 6c8a76b94..de322153d 100644
--- a/lib/Slic3r/Fill.pm
+++ b/lib/Slic3r/Fill.pm
@@ -209,7 +209,7 @@ sub make_fill {
             $h,
             $is_bridge,
             $layerm->id == 0,
-            undef,
+            -1,
             $layerm->object,
         );
         
diff --git a/lib/Slic3r/Layer/Region.pm b/lib/Slic3r/Layer/Region.pm
index eeaa40b5c..1c7838219 100644
--- a/lib/Slic3r/Layer/Region.pm
+++ b/lib/Slic3r/Layer/Region.pm
@@ -28,18 +28,6 @@ sub print   { return $_[0]->layer->print; }
 
 sub config  { return $_[0]->region->config; }
 
-sub flow {
-    my ($self, $role, $bridge, $width) = @_;
-    return $self->region->flow(
-        $role,
-        $self->layer->height,
-        $bridge // 0,
-        $self->layer->id == 0,
-        $width,
-        $self->object,
-    );
-}
-
 sub merge_slices {
     my ($self) = @_;
     
@@ -67,7 +55,7 @@ sub make_perimeters {
     my $ext_pspacing        = scale($ext_perimeter_flow->spacing_to($perimeter_flow));
     
     # overhang perimeters
-    my $overhang_flow       = $self->region->flow(FLOW_ROLE_PERIMETER, -1, 1, 0, undef, $self->layer->object);
+    my $overhang_flow       = $self->region->flow(FLOW_ROLE_PERIMETER, -1, 1, 0, -1, $self->layer->object);
     my $mm3_per_mm_overhang = $overhang_flow->mm3_per_mm;
     
     # solid infill
diff --git a/lib/Slic3r/Print.pm b/lib/Slic3r/Print.pm
index 71e591734..90fe5df22 100644
--- a/lib/Slic3r/Print.pm
+++ b/lib/Slic3r/Print.pm
@@ -737,20 +737,20 @@ sub write_gcode {
     my $layer_height = $first_object->config->layer_height;
     for my $region_id (0..$#{$self->regions}) {
         printf $fh "; external perimeters extrusion width = %.2fmm\n",
-            $self->regions->[$region_id]->flow(FLOW_ROLE_EXTERNAL_PERIMETER, $layer_height, 0, 0, undef, $first_object)->width;
+            $self->regions->[$region_id]->flow(FLOW_ROLE_EXTERNAL_PERIMETER, $layer_height, 0, 0, -1, $first_object)->width;
         printf $fh "; perimeters extrusion width = %.2fmm\n",
-            $self->regions->[$region_id]->flow(FLOW_ROLE_PERIMETER, $layer_height, 0, 0, undef, $first_object)->width;
+            $self->regions->[$region_id]->flow(FLOW_ROLE_PERIMETER, $layer_height, 0, 0, -1, $first_object)->width;
         printf $fh "; infill extrusion width = %.2fmm\n",
-            $self->regions->[$region_id]->flow(FLOW_ROLE_INFILL, $layer_height, 0, 0, undef, $first_object)->width;
+            $self->regions->[$region_id]->flow(FLOW_ROLE_INFILL, $layer_height, 0, 0, -1, $first_object)->width;
         printf $fh "; solid infill extrusion width = %.2fmm\n",
-            $self->regions->[$region_id]->flow(FLOW_ROLE_SOLID_INFILL, $layer_height, 0, 0, undef, $first_object)->width;
+            $self->regions->[$region_id]->flow(FLOW_ROLE_SOLID_INFILL, $layer_height, 0, 0, -1, $first_object)->width;
         printf $fh "; top infill extrusion width = %.2fmm\n",
-            $self->regions->[$region_id]->flow(FLOW_ROLE_TOP_SOLID_INFILL, $layer_height, 0, 0, undef, $first_object)->width;
+            $self->regions->[$region_id]->flow(FLOW_ROLE_TOP_SOLID_INFILL, $layer_height, 0, 0, -1, $first_object)->width;
         printf $fh "; support material extrusion width = %.2fmm\n",
             $self->objects->[0]->support_material_flow->width
             if $self->has_support_material;
         printf $fh "; first layer extrusion width = %.2fmm\n",
-            $self->regions->[$region_id]->flow(FLOW_ROLE_PERIMETER, $layer_height, 0, 1, undef, $self->objects->[0])->width
+            $self->regions->[$region_id]->flow(FLOW_ROLE_PERIMETER, $layer_height, 0, 1, -1, $self->objects->[0])->width
             if $self->regions->[$region_id]->config->first_layer_extrusion_width;
         print  $fh "\n";
     }
diff --git a/lib/Slic3r/Print/Region.pm b/lib/Slic3r/Print/Region.pm
deleted file mode 100644
index 5f591d883..000000000
--- a/lib/Slic3r/Print/Region.pm
+++ /dev/null
@@ -1,63 +0,0 @@
-package Slic3r::Print::Region;
-use strict;
-use warnings;
-
-use Slic3r::Extruder ':roles';
-use Slic3r::Flow ':roles';
-
-# A Print::Region object represents a group of volumes to print
-# sharing the same config (including the same assigned extruder(s))
-
-sub flow {
-    my ($self, $role, $layer_height, $bridge, $first_layer, $width, $object) = @_;
-    
-    $bridge         //= 0;
-    $first_layer    //= 0;
-    
-    # use the supplied custom width, if any
-    my $config_width = $width;
-    if (!defined $config_width) {
-        # get extrusion width from configuration
-        # (might be an absolute value, or a percent value, or zero for auto)
-        if ($first_layer && $self->print->config->first_layer_extrusion_width) {
-            $config_width = $self->print->config->first_layer_extrusion_width;
-        } elsif ($role == FLOW_ROLE_EXTERNAL_PERIMETER) {
-            $config_width = $self->config->external_perimeter_extrusion_width;
-        } elsif ($role == FLOW_ROLE_PERIMETER) {
-            $config_width = $self->config->perimeter_extrusion_width;
-        } elsif ($role == FLOW_ROLE_INFILL) {
-            $config_width = $self->config->infill_extrusion_width;
-        } elsif ($role == FLOW_ROLE_SOLID_INFILL) {
-            $config_width = $self->config->solid_infill_extrusion_width;
-        } elsif ($role == FLOW_ROLE_TOP_SOLID_INFILL) {
-            $config_width = $self->config->top_infill_extrusion_width;
-        } else {
-            die "Unknown role $role";
-        }
-    }
-    if ($config_width eq '0') {
-        $config_width = $object->config->extrusion_width;
-    }
-    
-    # get the configured nozzle_diameter for the extruder associated
-    # to the flow role requested
-    my $extruder;  # 1-based
-    if ($role == FLOW_ROLE_PERIMETER || $role == FLOW_ROLE_EXTERNAL_PERIMETER) {
-        $extruder = $self->config->perimeter_extruder;
-    } elsif ($role == FLOW_ROLE_INFILL || $role == FLOW_ROLE_SOLID_INFILL || $role == FLOW_ROLE_TOP_SOLID_INFILL) {
-        $extruder = $self->config->infill_extruder;
-    } else {
-        die "Unknown role $role";
-    }
-    my $nozzle_diameter = $self->print->config->get_at('nozzle_diameter', $extruder-1);
-    
-    return Slic3r::Flow->new_from_width(
-        width               => $config_width,
-        role                => $role,
-        nozzle_diameter     => $nozzle_diameter,
-        layer_height        => $layer_height,
-        bridge_flow_ratio   => ($bridge ? $self->config->bridge_flow_ratio : 0),
-    );
-}
-
-1;
diff --git a/xs/src/Layer.cpp b/xs/src/Layer.cpp
index 3df747250..107ff1be7 100644
--- a/xs/src/Layer.cpp
+++ b/xs/src/Layer.cpp
@@ -28,6 +28,19 @@ LayerRegion::region()
     return this->_region;
 }
 
+Flow
+LayerRegion::flow(FlowRole role, bool bridge, double width) const
+{
+    return this->_region->flow(
+        role,
+        this->_layer->height,
+        bridge,
+        this->_layer->id() == 0,
+        width,
+        *this->_layer->object()
+    );
+}
+
 #ifdef SLIC3RXS
 REGISTER_CLASS(LayerRegion, "Layer::Region");
 #endif
diff --git a/xs/src/Layer.hpp b/xs/src/Layer.hpp
index bfbaddc3c..cea1535b0 100644
--- a/xs/src/Layer.hpp
+++ b/xs/src/Layer.hpp
@@ -2,6 +2,7 @@
 #define slic3r_Layer_hpp_
 
 #include <myinit.h>
+#include "Flow.hpp"
 #include "SurfaceCollection.hpp"
 #include "ExtrusionEntityCollection.hpp"
 #include "ExPolygonCollection.hpp"
@@ -49,7 +50,9 @@ class LayerRegion
 
     // ordered collection of extrusion paths to fill surfaces
     ExtrusionEntityCollection fills;
-
+    
+    Flow flow(FlowRole role, bool bridge = false, double width = -1) const;
+    
     private:
     Layer *_layer;
     PrintRegion *_region;
diff --git a/xs/src/Print.cpp b/xs/src/Print.cpp
index a4b69be4c..eab745f7c 100644
--- a/xs/src/Print.cpp
+++ b/xs/src/Print.cpp
@@ -60,6 +60,52 @@ PrintRegion::print()
     return this->_print;
 }
 
+Flow
+PrintRegion::flow(FlowRole role, double layer_height, bool bridge, bool first_layer, double width, const PrintObject &object) const
+{
+    ConfigOptionFloatOrPercent config_width;
+    if (width != -1) {
+        // use the supplied custom width, if any
+        config_width.value = width;
+        config_width.percent = false;
+    } else {
+        // otherwise, get extrusion width from configuration
+        // (might be an absolute value, or a percent value, or zero for auto)
+        if (first_layer && this->_print->config.first_layer_extrusion_width.value > 0) {
+            config_width = this->_print->config.first_layer_extrusion_width;
+        } else if (role == frExternalPerimeter) {
+            config_width = this->config.external_perimeter_extrusion_width;
+        } else if (role == frPerimeter) {
+            config_width = this->config.perimeter_extrusion_width;
+        } else if (role == frInfill) {
+            config_width = this->config.infill_extrusion_width;
+        } else if (role == frSolidInfill) {
+            config_width = this->config.solid_infill_extrusion_width;
+        } else if (role == frTopSolidInfill) {
+            config_width = this->config.top_infill_extrusion_width;
+        } else {
+            CONFESS("Unknown role");
+        }
+    }
+    if (config_width.value == 0) {
+        config_width = object.config.extrusion_width;
+    }
+    
+    // get the configured nozzle_diameter for the extruder associated
+    // to the flow role requested
+    size_t extruder;  // 1-based
+    if (role == frPerimeter || role == frExternalPerimeter) {
+        extruder = this->config.perimeter_extruder;
+    } else if (role == frInfill || role == frSolidInfill || role == frTopSolidInfill) {
+        extruder = this->config.infill_extruder;
+    } else {
+        CONFESS("Unknown role $role");
+    }
+    double nozzle_diameter = this->_print->config.nozzle_diameter.get_at(extruder-1);
+    
+    return Flow::new_from_config_width(role, config_width, nozzle_diameter, layer_height, bridge ? this->config.bridge_flow_ratio : 0);
+}
+
 #ifdef SLIC3RXS
 REGISTER_CLASS(PrintRegion, "Print::Region");
 #endif
diff --git a/xs/src/Print.hpp b/xs/src/Print.hpp
index aa94ded66..8b2a45044 100644
--- a/xs/src/Print.hpp
+++ b/xs/src/Print.hpp
@@ -4,6 +4,7 @@
 #include <myinit.h>
 #include <set>
 #include <vector>
+#include "Flow.hpp"
 #include "PrintConfig.hpp"
 #include "Point.hpp"
 #include "Layer.hpp"
@@ -13,6 +14,7 @@
 namespace Slic3r {
 
 class Print;
+class PrintObject;
 class ModelObject;
 
 
@@ -47,6 +49,7 @@ class PrintRegion
     PrintRegionConfig config;
 
     Print* print();
+    Flow flow(FlowRole role, double layer_height, bool bridge, bool first_layer, double width, const PrintObject &object) const;
 
     private:
     Print* _print;
diff --git a/xs/xsp/Layer.xsp b/xs/xsp/Layer.xsp
index 7d297216f..8bdbef54f 100644
--- a/xs/xsp/Layer.xsp
+++ b/xs/xsp/Layer.xsp
@@ -26,6 +26,9 @@
         %code%{ RETVAL = &THIS->perimeters; %};
     Ref<ExtrusionEntityCollection> fills()
         %code%{ RETVAL = &THIS->fills; %};
+    
+    Flow* flow(FlowRole role, bool bridge = false, double width = -1)
+        %code%{ RETVAL = new Flow(THIS->flow(role, bridge, width)); %};
 };
 
 %name{Slic3r::Layer} class Layer {
diff --git a/xs/xsp/Print.xsp b/xs/xsp/Print.xsp
index 548123f75..39a094e55 100644
--- a/xs/xsp/Print.xsp
+++ b/xs/xsp/Print.xsp
@@ -34,6 +34,9 @@ _constant()
     Ref<PrintRegionConfig> config()
         %code%{ RETVAL = &THIS->config; %};
     Ref<Print> print();
+    
+    Flow* flow(FlowRole role, double layer_height, bool bridge, bool first_layer, double width, PrintObject* object)
+        %code%{ RETVAL = new Flow(THIS->flow(role, layer_height, bridge, first_layer, width, *object)); %};
 };