diff --git a/OpenNest.Core/CNC/CuttingStrategy/CuttingParameters.cs b/OpenNest.Core/CNC/CuttingStrategy/CuttingParameters.cs
index ddd33099..81c38dc5 100644
--- a/OpenNest.Core/CNC/CuttingStrategy/CuttingParameters.cs
+++ b/OpenNest.Core/CNC/CuttingStrategy/CuttingParameters.cs
@@ -81,9 +81,9 @@ namespace OpenNest.CNC.CuttingStrategy
         /// With <see cref="SupportTabs"/> on a plate with a support bed, the longest part (the
         /// long side of its outline's minimum-area bounding rectangle) its tab alone holds: such a
         /// part the bed cannot hold level is tabbed, and any tab clear of inside corners steadies
-        /// it. 0 turns the rule off.
+        /// it. 0 turns the rule off. New settings start at 6; settings saved without it read as 0.
         /// </summary>
-        public double TabHeldMaxLength { get; set; }
+        public double TabHeldMaxLength { get; set; } = 6;
 
         /// <summary>Whether a part <paramref name="length"/> long is held by its tab alone (see <see cref="TabHeldMaxLength"/>).</summary>
         public bool TabHoldsAt(double length) =>
diff --git a/OpenNest.Tests/Support/TabHeldSupportTabTests.cs b/OpenNest.Tests/Support/TabHeldSupportTabTests.cs
index cb89e874..c86ae53f 100644
--- a/OpenNest.Tests/Support/TabHeldSupportTabTests.cs
+++ b/OpenNest.Tests/Support/TabHeldSupportTabTests.cs
@@ -60,6 +60,35 @@ public class TabHeldSupportTabTests
         Assert.Equal(holdsALengthOfOneAndAHalf, new CuttingParameters { TabHeldMaxLength = max }.TabHoldsAt(1.5));
     }
 
+    [Theory]
+    [InlineData(0)]
+    [InlineData(45)]
+    [InlineData(90)]
+    [InlineData(135)]
+    [InlineData(180)]
+    [InlineData(270)]
+    [InlineData(315)]
+    public void LengthOfATriangleWithTwoLeastBoxes_DoesNotDependOnItsRotation(double degrees)
+    {
+        // A 5 x 5 right triangle fits its legs' square and its hypotenuse's 7.07 x 3.54 box, both
+        // of area 25: the squarer box is the one measured, whatever way the part is turned.
+        var triangle = new Program();
+        triangle.MoveTo(0, 0); triangle.LineTo(5, 0); triangle.LineTo(0, 5); triangle.LineTo(0, 0);
+        var part = new Part(new Drawing("gusset", triangle), new Vector(10, 10));
+        part.Rotate(degrees * System.Math.PI / 180);
+        var material = SupportMaterial.FromPart(part);
+
+        Assert.Equal(5, SupportAnalyzer.Length(material), 6);
+        Assert.Equal(5, SupportAnalyzer.Width(material), 6);
+    }
+
+    [Fact]
+    public void NewSettingsHoldPartsUpToSixLong()
+    {
+        Assert.Equal(6, new CuttingParameters().TabHeldMaxLength);
+        Assert.True(new CuttingParameters().TabHoldsAt(5));
+    }
+
     [Fact]
     public void Analyze_HoldsAShortPartTheBedCannotByAnyClearTab()
     {
diff --git a/docs/support-tabs.md b/docs/support-tabs.md
index 422e02ec..2790ad72 100644
--- a/docs/support-tabs.md
+++ b/docs/support-tabs.md
@@ -102,7 +102,12 @@ hold level whose length (the long side of its outline's minimum-area bounding re
 `SupportAnalyzer.Length`) is at most that, bound included, is still tabbed, but
 `SupportAnalyzer.HeldByTab` marks its analysis `IsHeldByTab`: it keeps its contacts and margin,
 every tab clear of inside corners steadies it, and its best tab point is chosen as on a plate
-with no bed (below). A part the bed holds is not tabbed. 0 turns the rule off.
+with no bed (below). A part the bed holds is not tabbed. 0 turns the rule off; new settings
+start at 6, while settings saved without the field read as 0, so saved settings keep their
+meaning. Some outlines have two minimum-area rectangles (a right isosceles triangle fits both
+its legs' square and its hypotenuse's 2:1 box), and which one rounding finds depends on how the
+part is turned; of rectangles tied for area, `SupportAnalyzer` measures the one with the shorter
+long side, so a drawing's length and width are the same at every rotation.
 `SupportTabSettings.Analyze` applies it for Plan Cutting, hand-placed lead-ins and the pre-post
 review alike, so such a part warns only when it is cut with no tab at all. View > Draw Support
 does not read cutting settings and still shows it red, since it would tip without its tab.