diff --git a/lib/Slic3r/Layer/Region.pm b/lib/Slic3r/Layer/Region.pm
index aedb45d02..027a9bd58 100644
--- a/lib/Slic3r/Layer/Region.pm
+++ b/lib/Slic3r/Layer/Region.pm
@@ -16,6 +16,7 @@ has 'layer' => (
 has 'region'            => (is => 'ro', required => 1);
 has 'perimeter_flow'    => (is => 'rw');
 has 'infill_flow'       => (is => 'rw');
+has 'infill_area_threshold' => (is => 'lazy');
 has 'overhang_width'    => (is => 'lazy');
 
 # collection of spare segments generated by slicing the original geometry;
@@ -71,6 +72,11 @@ sub _build_overhang_width {
     return scale($self->height * ((cos $threshold_rad) / (sin $threshold_rad)));
 }
 
+sub _build_infill_area_threshold {
+    my $self = shift;
+    return $self->infill_flow->scaled_spacing ** 2;
+}
+
 # build polylines from lines
 sub make_surfaces {
     my $self = shift;
@@ -194,7 +200,7 @@ sub make_perimeters {
                 # this compensation only works for circular holes, while it would 
                 # overcompensate for hexagons and other shapes having straight edges.
                 # so we require a minimum number of vertices.
-                next unless $circumference / @$hole >= 3 * $Slic3r::flow->scaled_width;
+                next unless $circumference / @$hole >= 3 * $self->perimeter_flow->scaled_width;
                 
                 # revert the compensation done in make_surfaces() and get the actual radius
                 # of the hole
@@ -411,7 +417,7 @@ sub _add_perimeter {
     my $self = shift;
     my ($polygon, $role) = @_;
     
-    return unless $polygon->is_printable($self->perimeter_flow->width);
+    return unless $polygon->is_printable($self->perimeter_flow);
     push @{ $self->perimeters }, Slic3r::ExtrusionLoop->pack(
         polygon         => $polygon,
         role            => ($role // EXTR_ROLE_PERIMETER),
diff --git a/lib/Slic3r/Polygon.pm b/lib/Slic3r/Polygon.pm
index 4cc51d610..da23e823a 100644
--- a/lib/Slic3r/Polygon.pm
+++ b/lib/Slic3r/Polygon.pm
@@ -118,7 +118,7 @@ sub subdivide {
 # returns false if the polyline is too tight to be printed
 sub is_printable {
     my $self = shift;
-    my ($flow_width) = @_;
+    my ($flow) = @_;
     
     # try to get an inwards offset
     # for a distance equal to half of the extrusion width;
@@ -129,7 +129,7 @@ sub is_printable {
     # detect them and we would be discarding them.
     my $p = $self->clone;
     $p->make_counter_clockwise;
-    return $p->offset(Slic3r::Geometry::scale($flow_width || $Slic3r::flow->width) / 2) ? 1 : 0;
+    return $p->offset($flow->scaled_width / 2) ? 1 : 0;
 }
 
 sub is_valid {
diff --git a/lib/Slic3r/Print/Object.pm b/lib/Slic3r/Print/Object.pm
index c4a02b196..a9fc25c34 100644
--- a/lib/Slic3r/Print/Object.pm
+++ b/lib/Slic3r/Print/Object.pm
@@ -306,7 +306,7 @@ sub detect_surfaces_type {
             [ map { ref $_ eq 'ARRAY' ? $_ : ref $_ eq 'Slic3r::ExPolygon' ? @$_ : $_->p } @$clip_surfaces ],
             1,
         );
-        return grep $_->contour->is_printable($layerm->flow->width),
+        return grep $_->contour->is_printable($layerm->flow),
             map Slic3r::Surface->new(expolygon => $_, surface_type => $result_type), 
             @$expolygons;
     };
@@ -430,8 +430,6 @@ sub discover_horizontal_shells {
     
     Slic3r::debugf "==> DISCOVERING HORIZONTAL SHELLS\n";
     
-    my $area_threshold = $Slic3r::flow->scaled_spacing ** 2;
-    
     for my $region_id (0 .. ($self->print->regions_count-1)) {
         for (my $i = 0; $i < $self->layer_count; $i++) {
             my $layerm = $self->layers->[$i]->regions->[$region_id];
@@ -514,6 +512,7 @@ sub discover_horizontal_shells {
                 }
             }
             
+            my $area_threshold = $layerm->infill_area_threshold;
             @{$layerm->fill_surfaces} = grep $_->expolygon->area > $area_threshold, @{$layerm->fill_surfaces};
         }
         
@@ -534,7 +533,6 @@ sub combine_infill {
     return unless $Slic3r::Config->infill_every_layers > 1 && $Slic3r::Config->fill_density > 0;
     
     my $every = $Slic3r::Config->infill_every_layers;
-    my $area_threshold = $Slic3r::flow->scaled_spacing ** 2;
     
     my $layer_count = $self->layer_count;
     for my $region_id (0 .. ($self->print->regions_count-1)) {
@@ -559,6 +557,7 @@ sub combine_infill {
                     );
                 }
                 
+                my $area_threshold = $layerms[0]->infill_area_threshold;
                 @$intersection = grep $_->area > $area_threshold, @$intersection;
                 next if !@$intersection;
                 Slic3r::debugf "  combining %d %s regions from layers %d-%d\n",