diff --git a/OpenNest.Core/Geometry/Shape.cs b/OpenNest.Core/Geometry/Shape.cs
index 21463511..e4cf126a 100644
--- a/OpenNest.Core/Geometry/Shape.cs
+++ b/OpenNest.Core/Geometry/Shape.cs
@@ -264,10 +264,24 @@ namespace OpenNest.Geometry
         }
 
         /// <summary>
-        /// Converts the shape to a polygon.
+        /// Maximum chord error, in drawing units, when <see cref="ToPolygon()"/> flattens arcs
+        /// and circles. Ten times tighter than the spacing/overlap checks' 0.001 because callers
+        /// use this polygon for area, and an inscribed polygon always reads low.
         /// </summary>
-        /// <returns></returns>
-        public Polygon ToPolygon(int arcSegments = 1000)
+        public const double DefaultChordTolerance = 0.0001;
+
+        /// <summary>
+        /// Converts the shape to a polygon, flattening arcs to within
+        /// <see cref="DefaultChordTolerance"/>. A fixed segment count per arc (formerly 1000)
+        /// made large arcs no more accurate and small ones needlessly dense: arc-heavy drawings
+        /// produced hundreds of thousands of vertices every time their area was computed.
+        /// </summary>
+        public Polygon ToPolygon() => ToPolygonWithTolerance(DefaultChordTolerance);
+
+        /// <summary>
+        /// Converts the shape to a polygon with a fixed number of segments per arc and circle.
+        /// </summary>
+        public Polygon ToPolygon(int arcSegments)
         {
             var polygon = new Polygon();
 
diff --git a/OpenNest.Core/Geometry/SpacingOutline.cs b/OpenNest.Core/Geometry/SpacingOutline.cs
index 8ee0545c..a89e812d 100644
--- a/OpenNest.Core/Geometry/SpacingOutline.cs
+++ b/OpenNest.Core/Geometry/SpacingOutline.cs
@@ -64,8 +64,8 @@ namespace OpenNest.Geometry
         public static SpacingOutline Build(ShapeProfile profile, Vector location, double inflateBy)
         {
             ArgumentNullException.ThrowIfNull(profile);
-            // Adaptive tolerance instead of Shape.ToPolygon()'s default (up to 1000 segments per
-            // arc): arc-heavy real parts otherwise produce thousands of vertices.
+            // Flatten by chord tolerance, not a fixed segment count: arc-heavy real parts
+            // otherwise produce thousands of vertices.
             var region = ClipperBridge.OffsetForValidation(
                 profile,
                 inflateBy > Tolerance.Epsilon ? inflateBy : 0,