diff --git a/MatterControlLib/DesignTools/Operations/Path/InflatePathObject3D.cs b/MatterControlLib/DesignTools/Operations/Path/InflatePathObject3D.cs
index 5baa95458..b1993c07d 100644
--- a/MatterControlLib/DesignTools/Operations/Path/InflatePathObject3D.cs
+++ b/MatterControlLib/DesignTools/Operations/Path/InflatePathObject3D.cs
@@ -120,16 +120,16 @@ namespace MatterHackers.MatterControl.DesignTools.Operations
 			VertexStorage = path.Offset(Inflate.Value(this), GetJoinType(Style));
 		}
 
-		internal static JoinType GetJoinType(ExpandStyles style)
+		public static JoinType GetJoinType(ExpandStyles style)
 		{
-			ClipperLib.JoinType joinType = ClipperLib.JoinType.jtMiter;
+			ClipperLib.JoinType joinType = JoinType.jtMiter;
 			switch (style)
 			{
 				case ExpandStyles.Flat:
-					joinType = ClipperLib.JoinType.jtSquare;
+					joinType = JoinType.jtSquare;
 					break;
 				case ExpandStyles.Round:
-					joinType = ClipperLib.JoinType.jtRound;
+					joinType = JoinType.jtRound;
 					break;
 			}
 
diff --git a/MatterControlLib/DesignTools/Primitives/BaseObject3D.cs b/MatterControlLib/DesignTools/Primitives/BaseObject3D.cs
index 0e5e1467f..f6e02974c 100644
--- a/MatterControlLib/DesignTools/Primitives/BaseObject3D.cs
+++ b/MatterControlLib/DesignTools/Primitives/BaseObject3D.cs
@@ -39,6 +39,7 @@ using MatterHackers.Agg.VertexSource;
 using MatterHackers.DataConverters2D;
 using MatterHackers.DataConverters3D;
 using MatterHackers.Localizations;
+using MatterHackers.MatterControl.DesignTools.Operations;
 using MatterHackers.MatterControl.PartPreviewWindow;
 using MatterHackers.PolygonMesh.Csg;
 using MatterHackers.PolygonMesh.Processors;
@@ -90,6 +91,9 @@ namespace MatterHackers.MatterControl.DesignTools
 		[Slider(0, 10, Easing.EaseType.Quadratic, snapDistance: .1)]
 		public DoubleOrExpression InfillAmount { get; set; } = 3;
 
+		[EnumDisplay(Mode = EnumDisplayAttribute.PresentationMode.Buttons)]
+		public ExpandStyles Style { get; set; } = ExpandStyles.Round;
+
 		[DisplayName("Height")]
 		[Slider(1, 50, Easing.EaseType.Quadratic, useSnappingGrid: true)]
 		public DoubleOrExpression ExtrusionHeight { get; set; } = 5;
@@ -368,18 +372,19 @@ namespace MatterHackers.MatterControl.DesignTools
 					var infillAmount = InfillAmount.Value(this);
 					var baseSize = BaseSize.Value(this);
 					var extrusionHeight = ExtrusionHeight.Value(this);
+					var joinType = InflatePathObject3D.GetJoinType(Style);
 					if (BaseType == BaseTypes.Outline
 						&& infillAmount > 0)
 					{
-						basePolygons = polysToOffset.Offset((baseSize + infillAmount) * scalingForClipper);
-						basePolygons = basePolygons.Offset(-infillAmount * scalingForClipper);
+						basePolygons = polysToOffset.Offset((baseSize + infillAmount) * scalingForClipper, joinType);
+						basePolygons = basePolygons.Offset(-infillAmount * scalingForClipper, joinType);
 					}
 					else
 					{
-						basePolygons = polysToOffset.Offset(baseSize * scalingForClipper);
+						basePolygons = polysToOffset.Offset(baseSize * scalingForClipper, joinType);
 					}
 
-					basePolygons = ClipperLib.Clipper.CleanPolygons(basePolygons, 10);
+					basePolygons = Clipper.CleanPolygons(basePolygons, 10);
 
 					VertexStorage rawVectorShape = basePolygons.PolygonToPathStorage();
 					var vectorShape = new VertexSourceApplyTransform(rawVectorShape, Affine.NewScaling(1.0 / scalingForClipper));
@@ -414,6 +419,7 @@ namespace MatterHackers.MatterControl.DesignTools
 			changeSet.Add(nameof(InfillAmount), BaseType == BaseTypes.Outline);
 			changeSet.Add(nameof(Centering), BaseType == BaseTypes.Circle);
 			changeSet.Add(nameof(ExtrusionHeight), BaseType != BaseTypes.None);
+			changeSet.Add(nameof(Style), BaseType != BaseTypes.Circle);
 
 			var vertexSource = GetVertexSource();
             var meshSource = this.Descendants<IObject3D>().Where((i) => i.Mesh != null);
diff --git a/MatterControlLib/PartPreviewWindow/View3D/Actions/SubtractPathObject3D.cs b/MatterControlLib/PartPreviewWindow/View3D/Actions/SubtractPathObject3D.cs
index c91076011..c61347e36 100644
--- a/MatterControlLib/PartPreviewWindow/View3D/Actions/SubtractPathObject3D.cs
+++ b/MatterControlLib/PartPreviewWindow/View3D/Actions/SubtractPathObject3D.cs
@@ -123,14 +123,17 @@ namespace MatterHackers.MatterControl.PartPreviewWindow.View3D
 					}
 
 					// set the mesh to show the path
-					var extrudeMesh = this.GetVertexSource().Extrude(Constants.PathPolygonsHeight);
-					if(extrudeMesh.Vertices.Count() > 5)
+					if (this.GetVertexSource() != null)
 					{
-						this.Mesh = extrudeMesh;
-					}
-					else
-					{
-						this.Mesh = null;
+						var extrudeMesh = this.GetVertexSource().Extrude(Constants.PathPolygonsHeight);
+						if (extrudeMesh.Vertices.Count() > 5)
+						{
+							this.Mesh = extrudeMesh;
+						}
+						else
+						{
+							this.Mesh = null;
+						}
 					}
 
 					UiThread.RunOnIdle(() =>
diff --git a/Submodules/agg-sharp b/Submodules/agg-sharp
index 0fee6ab0d..c2b8646bf 160000
--- a/Submodules/agg-sharp
+++ b/Submodules/agg-sharp
@@ -1 +1 @@
-Subproject commit 0fee6ab0d2d61107717114258b06182815bc11d7
+Subproject commit c2b8646bf496a0ecf99338e513cf96cb6fdeed17