diff --git a/OpenNest.Core/Geometry/Arc.cs b/OpenNest.Core/Geometry/Arc.cs
index 0ed1272..d51a4c9 100644
--- a/OpenNest.Core/Geometry/Arc.cs
+++ b/OpenNest.Core/Geometry/Arc.cs
@@ -267,6 +267,13 @@ namespace OpenNest.Geometry
             get { return Diameter * System.Math.PI * SweepAngle() / Angle.TwoPI; }
         }
 
+        public override Entity Clone()
+        {
+            var copy = new Arc(center, radius, startAngle, endAngle, reversed);
+            CopyBaseTo(copy);
+            return copy;
+        }
+
         /// <summary>
         /// Reverses the rotation direction.
         /// </summary>
diff --git a/OpenNest.Core/Geometry/Circle.cs b/OpenNest.Core/Geometry/Circle.cs
index 05a03de..ac25197 100644
--- a/OpenNest.Core/Geometry/Circle.cs
+++ b/OpenNest.Core/Geometry/Circle.cs
@@ -165,6 +165,13 @@ namespace OpenNest.Geometry
             get { return Circumference(); }
         }
 
+        public override Entity Clone()
+        {
+            var copy = new Circle(center, radius) { Rotation = Rotation };
+            CopyBaseTo(copy);
+            return copy;
+        }
+
         /// <summary>
         /// Reverses the rotation direction.
         /// </summary>
diff --git a/OpenNest.Core/Geometry/Entity.cs b/OpenNest.Core/Geometry/Entity.cs
index bd2e7fe..723ddc6 100644
--- a/OpenNest.Core/Geometry/Entity.cs
+++ b/OpenNest.Core/Geometry/Entity.cs
@@ -251,6 +251,23 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public abstract bool Intersects(Shape shape, out List<Vector> pts);
 
+        /// <summary>
+        /// Creates a deep copy of the entity with a new Id.
+        /// </summary>
+        public abstract Entity Clone();
+
+        /// <summary>
+        /// Copies common Entity properties from this instance to the target.
+        /// </summary>
+        protected void CopyBaseTo(Entity target)
+        {
+            target.Color = Color;
+            target.Layer = Layer;
+            target.LineTypeName = LineTypeName;
+            target.IsVisible = IsVisible;
+            target.Tag = Tag;
+        }
+
         /// <summary>
         /// Type of entity.
         /// </summary>
@@ -259,6 +276,14 @@ namespace OpenNest.Geometry
 
     public static class EntityExtensions
     {
+        public static List<Entity> CloneAll(this IEnumerable<Entity> entities)
+        {
+            var result = new List<Entity>();
+            foreach (var e in entities)
+                result.Add(e.Clone());
+            return result;
+        }
+
         public static List<Vector> CollectPoints(this IEnumerable<Entity> entities)
         {
             var points = new List<Vector>();
diff --git a/OpenNest.Core/Geometry/Line.cs b/OpenNest.Core/Geometry/Line.cs
index e0317d8..9b4474b 100644
--- a/OpenNest.Core/Geometry/Line.cs
+++ b/OpenNest.Core/Geometry/Line.cs
@@ -257,6 +257,13 @@ namespace OpenNest.Geometry
             }
         }
 
+        public override Entity Clone()
+        {
+            var copy = new Line(pt1, pt2);
+            CopyBaseTo(copy);
+            return copy;
+        }
+
         /// <summary>
         /// Reversed the line.
         /// </summary>
diff --git a/OpenNest.Core/Geometry/Polygon.cs b/OpenNest.Core/Geometry/Polygon.cs
index 22e2131..9ae1cab 100644
--- a/OpenNest.Core/Geometry/Polygon.cs
+++ b/OpenNest.Core/Geometry/Polygon.cs
@@ -168,6 +168,13 @@ namespace OpenNest.Geometry
             get { return Perimeter(); }
         }
 
+        public override Entity Clone()
+        {
+            var copy = new Polygon { Vertices = new List<Vector>(Vertices) };
+            CopyBaseTo(copy);
+            return copy;
+        }
+
         /// <summary>
         /// Reverses the rotation direction of the polygon.
         /// </summary>
diff --git a/OpenNest.Core/Geometry/Shape.cs b/OpenNest.Core/Geometry/Shape.cs
index 6e35f1c..6cd9358 100644
--- a/OpenNest.Core/Geometry/Shape.cs
+++ b/OpenNest.Core/Geometry/Shape.cs
@@ -349,6 +349,15 @@ namespace OpenNest.Geometry
             return polygon;
         }
 
+        public override Entity Clone()
+        {
+            var copy = new Shape();
+            foreach (var e in Entities)
+                copy.Entities.Add(e.Clone());
+            CopyBaseTo(copy);
+            return copy;
+        }
+
         /// <summary>
         /// Reverses the rotation direction of the shape.
         /// </summary>
diff --git a/OpenNest.Core/Geometry/ShapeProfile.cs b/OpenNest.Core/Geometry/ShapeProfile.cs
index 23928e6..e73632d 100644
--- a/OpenNest.Core/Geometry/ShapeProfile.cs
+++ b/OpenNest.Core/Geometry/ShapeProfile.cs
@@ -75,7 +75,8 @@ namespace OpenNest.Geometry
         /// </summary>
         public static List<Entity> NormalizeEntities(IEnumerable<Entity> entities)
         {
-            var profile = new ShapeProfile(entities.ToList());
+            var cloned = entities.CloneAll();
+            var profile = new ShapeProfile(cloned);
             return profile.ToNormalizedEntities();
         }
 
diff --git a/OpenNest.Core/PartGeometry.cs b/OpenNest.Core/PartGeometry.cs
index c30f6e0..573d641 100644
--- a/OpenNest.Core/PartGeometry.cs
+++ b/OpenNest.Core/PartGeometry.cs
@@ -126,20 +126,10 @@ namespace OpenNest
         {
             var result = new List<Entity>(source.Count);
 
-            for (var i = 0; i < source.Count; i++)
+            foreach (var entity in source)
             {
-                var entity = source[i];
-                Entity copy;
-
-                if (entity is Line line)
-                    copy = new Line(line.StartPoint + location, line.EndPoint + location);
-                else if (entity is Arc arc)
-                    copy = new Arc(arc.Center + location, arc.Radius, arc.StartAngle, arc.EndAngle, arc.IsReversed);
-                else if (entity is Circle circle)
-                    copy = new Circle(circle.Center + location, circle.Radius);
-                else
-                    continue;
-
+                var copy = entity.Clone();
+                copy.Offset(location);
                 result.Add(copy);
             }
 
diff --git a/OpenNest/Controls/ProgramEditorControl.cs b/OpenNest/Controls/ProgramEditorControl.cs
index 0941463..0b026aa 100644
--- a/OpenNest/Controls/ProgramEditorControl.cs
+++ b/OpenNest/Controls/ProgramEditorControl.cs
@@ -209,15 +209,8 @@ namespace OpenNest.Controls
 
         private static Entity CloneEntity(Entity entity, Color color)
         {
-            Entity clone = entity switch
-            {
-                Line line => new Line(line.StartPoint, line.EndPoint) { Layer = line.Layer, IsVisible = line.IsVisible },
-                Arc arc => new Arc(arc.Center, arc.Radius, arc.StartAngle, arc.EndAngle, arc.IsReversed) { Layer = arc.Layer, IsVisible = arc.IsVisible },
-                Circle circle => new Circle(circle.Center, circle.Radius) { Layer = circle.Layer, IsVisible = circle.IsVisible },
-                _ => null,
-            };
-            if (clone != null)
-                clone.Color = color;
+            var clone = entity.Clone();
+            clone.Color = color;
             return clone;
         }