diff --git a/OpenNest.Data/NestMaterialSelection.cs b/OpenNest.Data/NestMaterialSelection.cs
new file mode 100644
index 0000000..c9aefef
--- /dev/null
+++ b/OpenNest.Data/NestMaterialSelection.cs
@@ -0,0 +1,25 @@
+namespace OpenNest.Data;
+
+/// <summary>
+/// Chooses the nest material when the Nest Info dialog is accepted. The dialog
+/// edits only the material name, so grade and density must come from the
+/// material the nest already has.
+/// </summary>
+public static class NestMaterialSelection
+{
+    /// <summary>
+    /// Returns a new material named <paramref name="selectedName"/>. When that
+    /// name matches the current material's name by <see cref="SharedListNames.Key"/>,
+    /// the current grade and density are kept; any other name gets a name-only
+    /// material. The current material is never modified or returned.
+    /// </summary>
+    public static Material Apply(Material? current, string? selectedName)
+    {
+        var name = selectedName ?? "";
+
+        if (current != null && SharedListNames.Key(current.Name) == SharedListNames.Key(name))
+            return new Material(name, current.Grade, current.Density);
+
+        return new Material(name);
+    }
+}
diff --git a/OpenNest.Data/SharedListNames.cs b/OpenNest.Data/SharedListNames.cs
new file mode 100644
index 0000000..8533f30
--- /dev/null
+++ b/OpenNest.Data/SharedListNames.cs
@@ -0,0 +1,18 @@
+namespace OpenNest.Data;
+
+/// <summary>
+/// Normalized matching key for names in company lists (customers, materials).
+/// </summary>
+public static class SharedListNames
+{
+    /// <summary>
+    /// Returns the name trimmed, with internal whitespace runs collapsed to one
+    /// space, in invariant upper case. Names that differ only in spacing or case
+    /// share a key. A null or blank name has the empty key.
+    /// </summary>
+    public static string Key(string? name) =>
+        name == null
+            ? ""
+            : string.Join(' ', name.Split((char[]?)null, StringSplitOptions.RemoveEmptyEntries))
+                .ToUpperInvariant();
+}
diff --git a/OpenNest.Tests/Data/NestMaterialSelectionTests.cs b/OpenNest.Tests/Data/NestMaterialSelectionTests.cs
new file mode 100644
index 0000000..243855a
--- /dev/null
+++ b/OpenNest.Tests/Data/NestMaterialSelectionTests.cs
@@ -0,0 +1,90 @@
+using OpenNest.Data;
+
+namespace OpenNest.Tests.Data;
+
+public class NestMaterialSelectionTests
+{
+    [Fact]
+    public void Apply_UnchangedName_KeepsGradeAndDensity()
+    {
+        var current = new Material("Stainless", "304", 0.289);
+
+        var result = NestMaterialSelection.Apply(current, "Stainless");
+
+        Assert.Equal("Stainless", result.Name);
+        Assert.Equal("304", result.Grade);
+        Assert.Equal(0.289, result.Density);
+    }
+
+    [Fact]
+    public void Apply_NameDifferingOnlyInSpacingAndCase_KeepsGradeAndDensityAndTakesTypedName()
+    {
+        var current = new Material("Cold Rolled Steel", "1008", 0.284);
+
+        var result = NestMaterialSelection.Apply(current, " cold  rolled\tsteel ");
+
+        Assert.Equal(" cold  rolled\tsteel ", result.Name);
+        Assert.Equal("1008", result.Grade);
+        Assert.Equal(0.284, result.Density);
+    }
+
+    [Fact]
+    public void Apply_ChangedName_GetsNameOnly()
+    {
+        var current = new Material("Stainless", "304", 0.289);
+
+        var result = NestMaterialSelection.Apply(current, "Aluminum");
+
+        Assert.Equal("Aluminum", result.Name);
+        Assert.True(string.IsNullOrEmpty(result.Grade));
+        Assert.Equal(0, result.Density);
+    }
+
+    [Fact]
+    public void Apply_ClearedName_GetsEmptyNameOnly()
+    {
+        var current = new Material("Stainless", "304", 0.289);
+
+        var result = NestMaterialSelection.Apply(current, "");
+
+        Assert.Equal("", result.Name);
+        Assert.True(string.IsNullOrEmpty(result.Grade));
+        Assert.Equal(0, result.Density);
+    }
+
+    [Fact]
+    public void Apply_NoCurrentMaterial_GetsNameOnly()
+    {
+        var result = NestMaterialSelection.Apply(null, "Stainless");
+
+        Assert.Equal("Stainless", result.Name);
+        Assert.True(string.IsNullOrEmpty(result.Grade));
+        Assert.Equal(0, result.Density);
+    }
+
+    [Fact]
+    public void Apply_ReturnsCopy_LeavingCurrentMaterialUnchanged()
+    {
+        var current = new Material("Stainless", "304", 0.289);
+
+        var result = NestMaterialSelection.Apply(current, "stainless");
+        result.Grade = "316";
+        result.Density = 1;
+
+        Assert.NotSame(current, result);
+        Assert.Equal("Stainless", current.Name);
+        Assert.Equal("304", current.Grade);
+        Assert.Equal(0.289, current.Density);
+    }
+
+    [Theory]
+    [InlineData("Carbon Steel", "CARBON STEEL")]
+    [InlineData("  carbon \t steel\n", "CARBON STEEL")]
+    [InlineData("", "")]
+    [InlineData("   ", "")]
+    [InlineData(null, "")]
+    public void SharedListNamesKey_TrimsCollapsesWhitespaceAndUppercases(string? name, string expected)
+    {
+        Assert.Equal(expected, SharedListNames.Key(name));
+    }
+}
diff --git a/OpenNest.WinForms.Tests/Forms/EditNestInfoFormTests.cs b/OpenNest.WinForms.Tests/Forms/EditNestInfoFormTests.cs
new file mode 100644
index 0000000..44bb9a8
--- /dev/null
+++ b/OpenNest.WinForms.Tests/Forms/EditNestInfoFormTests.cs
@@ -0,0 +1,44 @@
+using OpenNest.Forms;
+
+namespace OpenNest.WinForms.Tests.Forms;
+
+public class EditNestInfoFormTests
+{
+    [Fact]
+    public void SaveWithUnchangedMaterial_KeepsGradeAndDensity()
+    {
+        RunSta(() =>
+        {
+            var nest = new Nest { Material = new Material("Stainless", "304", 0.289) };
+            using var form = new EditNestInfoForm();
+            form.LoadNestInfo(nest);
+
+            form.SaveNestInfo(nest);
+
+            Assert.Equal("Stainless", nest.Material.Name);
+            Assert.Equal("304", nest.Material.Grade);
+            Assert.Equal(0.289, nest.Material.Density);
+        });
+    }
+
+    [Fact]
+    public void SaveWithChangedMaterial_GetsNameOnly()
+    {
+        RunSta(() =>
+        {
+            var nest = new Nest { Material = new Material("Stainless", "304", 0.289) };
+            using var form = new EditNestInfoForm();
+            form.LoadNestInfo(nest);
+            form.MaterialName = "Aluminum";
+
+            form.SaveNestInfo(nest);
+
+            Assert.Equal("Aluminum", nest.Material.Name);
+            Assert.True(string.IsNullOrEmpty(nest.Material.Grade));
+            Assert.Equal(0, nest.Material.Density);
+        });
+    }
+
+    private static void RunSta(Action action) =>
+        StaTestThread.Run(action, TimeSpan.FromSeconds(15), "The STA test did not complete.");
+}
diff --git a/OpenNest/Forms/EditNestInfoForm.cs b/OpenNest/Forms/EditNestInfoForm.cs
index f1d38af..3cd4f62 100644
--- a/OpenNest/Forms/EditNestInfoForm.cs
+++ b/OpenNest/Forms/EditNestInfoForm.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Windows.Forms;
+using OpenNest.Data;
 using OpenNest.Geometry;
 using Timer = System.Timers.Timer;
 
@@ -238,7 +239,7 @@ namespace OpenNest.Forms
             nest.DateCreated = DateCreated;
             nest.DateLastModified = DateLastModified;
             nest.Thickness = Thickness;
-            nest.Material = new Material(MaterialName);
+            nest.Material = NestMaterialSelection.Apply(nest.Material, MaterialName);
             nest.Status = Status;
             nest.MadeBy = MadeBy;
             nest.PlateDefaults.Size = OpenNest.Geometry.Size.Parse(SizeString);