diff --git a/OpenNest.WinForms.Tests/Forms/BomImportFormTests.cs b/OpenNest.WinForms.Tests/Forms/BomImportFormTests.cs
index 9274ee0..6a7b71c 100644
--- a/OpenNest.WinForms.Tests/Forms/BomImportFormTests.cs
+++ b/OpenNest.WinForms.Tests/Forms/BomImportFormTests.cs
@@ -1,13 +1,211 @@
 using System.Data;
 using System.Reflection;
+using System.Runtime.InteropServices;
+using System.Text;
 using System.Windows.Forms;
 using OpenNest.Forms;
 using OpenNest.IO.Bom;
 
 namespace OpenNest.WinForms.Tests.Forms;
 
+[Collection("Fill operation lifetime")]
 public class BomImportFormTests
 {
+    [Fact]
+    public void FileNameWithDxfExtension_RealRowBuilderShowsReady()
+    {
+        RunSta(() =>
+        {
+            using var files = new WindowsAcceptanceFiles();
+            var path = files.WriteSquare("acceptance-square");
+            var row = Assert.Single(BomImportRows.Build(
+                new List<BomItem> { Item("acceptance-square.dxf", qty: 2) }, files.Folder));
+            using var form = Show(out var parts);
+
+            form.LoadRows(new[] { row });
+
+            Assert.True(form.Visible);
+            Assert.Equal(path, row.DxfPath);
+            Assert.Same(row, parts.Rows[0].DataBoundItem);
+            Assert.Equal("acceptance-square.dxf", parts.Rows[0].Cells["colFileName"].Value);
+            Assert.Equal("Ready", parts.Rows[0].Cells["colStatus"].Value);
+            Assert.Equal(BomRowStatus.Ready, row.Status);
+            Assert.Single(GroupsTable(form).Rows);
+            Assert.Equal(2, GroupTotal(form, 0));
+            Assert.True(Field<Button>(form, "btnCreateNests").Enabled);
+        });
+    }
+
+    [Fact]
+    public void BlankThickness_RealRowBuilderResolvesDrawingAndGridEditMakesReadyGroup()
+    {
+        RunSta(() =>
+        {
+            using var files = new WindowsAcceptanceFiles();
+            var path = files.WriteSquare("acceptance-square");
+            var item = Item("acceptance-square", qty: 3);
+            item.Thickness = null;
+            var row = Assert.Single(BomImportRows.Build(new List<BomItem> { item }, files.Folder));
+            using var form = Show(out var parts);
+            form.LoadRows(new[] { row });
+
+            Assert.True(form.Visible);
+            Assert.Equal(path, row.DxfPath);
+            Assert.Null(row.Thickness);
+            Assert.True(row.IsEditable);
+            Assert.Equal("Needs thickness", parts.Rows[0].Cells["colStatus"].Value);
+            Assert.Empty(GroupsTable(form).Rows);
+            Assert.False(Field<Button>(form, "btnCreateNests").Enabled);
+
+            Assert.True(Edit(parts, 0, "colThickness", 0.25.ToString()));
+
+            Assert.Equal(0.25, row.Thickness);
+            Assert.Equal(BomRowStatus.Ready, row.Status);
+            Assert.Equal("Ready", parts.Rows[0].Cells["colStatus"].Value);
+            var group = Assert.Single(GroupsTable(form).Rows.Cast<DataRow>());
+            Assert.Equal("Stainless", group["Material"]);
+            Assert.Equal(0.25, group["Thickness"]);
+            Assert.Equal(1, group["Parts"]);
+            Assert.Equal(3, group["Total Qty"]);
+            Assert.Equal("1 ready", Field<Label>(form, "lblSummary").Text);
+            Assert.True(Field<Button>(form, "btnCreateNests").Enabled);
+        });
+    }
+
+    [Fact]
+    public void DuplicateRows_CreateNestsButtonImportsOneDrawingWithCombinedQuantity()
+    {
+        RunSta(() =>
+        {
+            using var files = new WindowsAcceptanceFiles();
+            var path = files.WriteSquare("acceptance-square");
+            var rows = BomImportRows.Build(
+                new List<BomItem>
+                {
+                    Item("acceptance-square", qty: 2),
+                    Item("acceptance-square.dxf", qty: 3),
+                }, files.Folder);
+            using var host = new Form { IsMdiContainer = true };
+            host.Show();
+            using var form = Show(out var parts);
+            form.MdiParentForm = host;
+            Field<TextBox>(form, "txtJobName").Text = "Acceptance job";
+            Field<TextBox>(form, "txtPlateWidth").Text = "10";
+            Field<TextBox>(form, "txtPlateLength").Text = "20";
+            form.LoadRows(rows);
+
+            Assert.Equal(2, parts.Rows.Count);
+            Assert.All(rows, row => Assert.Equal(path, row.DxfPath));
+            Assert.Equal(5, GroupTotal(form, 0));
+            var create = Field<Button>(form, "btnCreateNests");
+            Assert.True(create.Enabled);
+
+            // The production event ends in a native MessageBox. A timer in
+            // its modal loop clicks that thread's real OK button, retaining
+            // the actual result text; no builder or success result is stubbed.
+            var dialogTitle = "";
+            var dialogText = "";
+            var okPosted = false;
+            var deadline = DateTime.UtcNow.AddSeconds(10);
+            using var dismiss = new System.Windows.Forms.Timer { Interval = 20 };
+            dismiss.Tick += (_, _) =>
+            {
+                EnumThreadWindows(GetCurrentThreadId(), (window, _) =>
+                {
+                    var className = new StringBuilder(256);
+                    GetClassName(window, className, className.Capacity);
+                    if (className.ToString() != "#32770")
+                        return true;
+
+                    dialogTitle = WindowText(window);
+                    var text = FindWindowEx(window, IntPtr.Zero, "Static", null);
+                    while (text != IntPtr.Zero)
+                    {
+                        var value = WindowText(text);
+                        if (!string.IsNullOrEmpty(value))
+                            dialogText += value;
+                        text = FindWindowEx(window, text, "Static", null);
+                    }
+                    var ok = GetDlgItem(window, 1);
+                    okPosted = ok != IntPtr.Zero && PostMessage(ok, 0x00F5, IntPtr.Zero, IntPtr.Zero);
+                    dismiss.Stop();
+                    return false;
+                }, IntPtr.Zero);
+                if (DateTime.UtcNow >= deadline && !okPosted)
+                    throw new TimeoutException("The Create Nests result dialog could not be acknowledged.");
+            };
+
+            try
+            {
+                dismiss.Start();
+                create.PerformClick();
+                dismiss.Stop();
+
+                Assert.True(okPosted, "Create Nests did not show its result dialog.");
+                Assert.Equal("Import Complete", dialogTitle);
+                Assert.Equal("1 nest created.", dialogText);
+                Assert.False(form.Visible);
+                var editor = Assert.IsType<EditNestForm>(Assert.Single(host.MdiChildren));
+                Assert.True(editor.Visible);
+                var nest = editor.Nest;
+                var drawing = Assert.Single(nest.Drawings);
+                Assert.Equal("acceptance-square", drawing.Name);
+                Assert.Equal(5, drawing.Quantity.Required);
+                Assert.NotEmpty(drawing.Program.Codes);
+                Assert.Equal(4, drawing.Area, precision: 6);
+                Assert.Equal($"Acceptance job - {0.25:0.####} Stainless", nest.Name);
+                Assert.Equal("Stainless", nest.Material.Name);
+                Assert.Equal(0.25, nest.Thickness);
+            }
+            finally
+            {
+                dismiss.Stop();
+                foreach (var child in host.MdiChildren)
+                    child.Dispose();
+            }
+        });
+    }
+
+    private static BomItem Item(string fileName, int qty) => new()
+    {
+        FileName = fileName,
+        Material = "Stainless",
+        Thickness = 0.25,
+        Qty = qty,
+    };
+
+    private static string WindowText(IntPtr window)
+    {
+        var text = new StringBuilder(1024);
+        GetWindowText(window, text, text.Capacity);
+        return text.ToString();
+    }
+
+    private delegate bool EnumThreadWindowCallback(IntPtr window, IntPtr parameter);
+
+    [DllImport("kernel32.dll")]
+    private static extern uint GetCurrentThreadId();
+
+    [DllImport("user32.dll")]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool EnumThreadWindows(uint threadId, EnumThreadWindowCallback callback, IntPtr parameter);
+
+    [DllImport("user32.dll", CharSet = CharSet.Unicode)]
+    private static extern int GetClassName(IntPtr window, StringBuilder className, int capacity);
+
+    [DllImport("user32.dll", CharSet = CharSet.Unicode)]
+    private static extern int GetWindowText(IntPtr window, StringBuilder text, int capacity);
+
+    [DllImport("user32.dll", CharSet = CharSet.Unicode)]
+    private static extern IntPtr FindWindowEx(IntPtr parent, IntPtr after, string className, string? title);
+
+    [DllImport("user32.dll")]
+    private static extern IntPtr GetDlgItem(IntPtr dialog, int id);
+
+    [DllImport("user32.dll", CharSet = CharSet.Unicode)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool PostMessage(IntPtr window, uint message, IntPtr wParam, IntPtr lParam);
+
     [Fact]
     public void PartColumns_KeepBomOrderAndOnlyMaterialThicknessAndQtyAreEditable()
     {
diff --git a/OpenNest.WinForms.Tests/Forms/EditNestInfoFormTests.cs b/OpenNest.WinForms.Tests/Forms/EditNestInfoFormTests.cs
index 44bb9a8..8a550c3 100644
--- a/OpenNest.WinForms.Tests/Forms/EditNestInfoFormTests.cs
+++ b/OpenNest.WinForms.Tests/Forms/EditNestInfoFormTests.cs
@@ -1,9 +1,127 @@
+using System.Runtime.ExceptionServices;
+using System.Windows.Forms;
 using OpenNest.Forms;
 
 namespace OpenNest.WinForms.Tests.Forms;
 
+[Collection("Fill operation lifetime")]
 public class EditNestInfoFormTests
 {
+    [Fact]
+    public void ShownEditorOk_FileRoundTripPreservesUnchangedMaterialGradeAndDensity()
+    {
+        RunSta(() =>
+        {
+            using var files = new WindowsAcceptanceFiles();
+            var nest = AcceptanceNest();
+
+            AcceptShownEditor(nest, materialName: null);
+
+            Assert.Equal("Stainless", nest.Material.Name);
+            Assert.Equal("304", nest.Material.Grade);
+            Assert.Equal(0.289, nest.Material.Density);
+            var restored = files.RoundTrip(nest);
+            Assert.Equal("Stainless", restored.Material.Name);
+            Assert.Equal("304", restored.Material.Grade);
+            Assert.Equal(0.289, restored.Material.Density);
+            Assert.Equal("Acceptance nest", restored.Name);
+        });
+    }
+
+    [Fact]
+    public void ShownEditorOk_FileRoundTripClearsOldMetadataWhenMaterialNameChanges()
+    {
+        RunSta(() =>
+        {
+            using var files = new WindowsAcceptanceFiles();
+            var nest = AcceptanceNest();
+
+            AcceptShownEditor(nest, materialName: "Aluminum");
+
+            Assert.Equal("Aluminum", nest.Material.Name);
+            Assert.True(string.IsNullOrEmpty(nest.Material.Grade));
+            Assert.Equal(0, nest.Material.Density);
+            var restored = files.RoundTrip(nest);
+            Assert.Equal("Aluminum", restored.Material.Name);
+            Assert.True(string.IsNullOrEmpty(restored.Material.Grade));
+            Assert.Equal(0, restored.Material.Density);
+            Assert.Equal("Acceptance nest", restored.Name);
+        });
+    }
+
+    private static Nest AcceptanceNest()
+    {
+        var nest = new Nest("Acceptance nest")
+        {
+            Material = new Material("Stainless", "304", 0.289),
+            Thickness = 0.25,
+            Units = Units.Inches,
+        };
+        nest.PlateDefaults.Size = new Geometry.Size(10, 20);
+        nest.CreatePlate();
+        return nest;
+    }
+
+    private static void AcceptShownEditor(Nest nest, string? materialName)
+    {
+        using var editor = new EditNestForm(nest);
+        editor.Show();
+        Assert.True(editor.Visible);
+        EditNestInfoForm? info = null;
+        Exception? failure = null;
+        var deadline = DateTime.UtcNow.AddSeconds(10);
+        using var accept = new System.Windows.Forms.Timer { Interval = 20 };
+        accept.Tick += (_, _) =>
+        {
+            info = Application.OpenForms.OfType<EditNestInfoForm>().SingleOrDefault();
+            if (info == null)
+            {
+                if (DateTime.UtcNow >= deadline)
+                    throw new TimeoutException("The Nest Info editor was not shown.");
+                return;
+            }
+
+            accept.Stop();
+            try
+            {
+                Assert.True(info.Visible);
+                Assert.True(info.Modal);
+                if (materialName != null)
+                    Assert.IsType<ComboBox>(info.Controls.Find("materialBox", true).Single()).Text = materialName;
+                info.EnableCheck();
+                var ok = Assert.IsType<Button>(info.Controls.Find("applyButton", true).Single());
+                Assert.True(ok.Enabled);
+                Assert.Equal(DialogResult.OK, ok.DialogResult);
+                ok.PerformClick();
+            }
+            catch (Exception ex)
+            {
+                failure = ex;
+                info.DialogResult = DialogResult.Cancel;
+                info.Close();
+            }
+        };
+
+        try
+        {
+            accept.Start();
+            // This is the live Nest Info entry point; it owns LoadNestInfo,
+            // ShowDialog and SaveNestInfo after the actual OK button accepts.
+            editor.ShowNestInfoEditor();
+            accept.Stop();
+            if (failure != null)
+                ExceptionDispatchInfo.Capture(failure).Throw();
+            Assert.NotNull(info);
+            Assert.Equal(DialogResult.OK, info.DialogResult);
+            Assert.False(info.Visible);
+        }
+        finally
+        {
+            accept.Stop();
+            info?.Dispose();
+        }
+    }
+
     [Fact]
     public void SaveWithUnchangedMaterial_KeepsGradeAndDensity()
     {
diff --git a/OpenNest.WinForms.Tests/Forms/WindowsAcceptanceFiles.cs b/OpenNest.WinForms.Tests/Forms/WindowsAcceptanceFiles.cs
new file mode 100644
index 0000000..fda10b4
--- /dev/null
+++ b/OpenNest.WinForms.Tests/Forms/WindowsAcceptanceFiles.cs
@@ -0,0 +1,48 @@
+using OpenNest.Converters;
+using OpenNest.Geometry;
+using OpenNest.IO;
+
+namespace OpenNest.WinForms.Tests.Forms;
+
+/// <summary>Private, synthetic files only; removed after each acceptance case.</summary>
+internal sealed class WindowsAcceptanceFiles : IDisposable
+{
+    public string Folder { get; } = Path.Combine(Path.GetTempPath(), "opennest-acceptance-" + Guid.NewGuid().ToString("N"));
+
+    public WindowsAcceptanceFiles()
+    {
+        Directory.CreateDirectory(Folder);
+    }
+
+    public string WriteSquare(string name)
+    {
+        var shape = new Shape();
+        shape.Entities.Add(new Line(new Vector(0, 0), new Vector(2, 0)));
+        shape.Entities.Add(new Line(new Vector(2, 0), new Vector(2, 2)));
+        shape.Entities.Add(new Line(new Vector(2, 2), new Vector(0, 2)));
+        shape.Entities.Add(new Line(new Vector(0, 2), new Vector(0, 0)));
+        var path = Path.Combine(Folder, name + ".dxf");
+        Dxf.ExportProgram(ConvertGeometry.ToProgram(shape), path);
+        Assert.True(File.Exists(path));
+        return path;
+    }
+
+    public Nest RoundTrip(Nest nest)
+    {
+        var path = Path.Combine(Folder, "acceptance.nest");
+        Assert.True(new NestWriter(nest).Write(path));
+        Assert.True(File.Exists(path));
+        Assert.True(new FileInfo(path).Length > 0);
+        using var stream = File.OpenRead(path);
+        var reader = new NestReader(stream);
+        var restored = reader.Read();
+        Assert.Empty(reader.Warnings);
+        Assert.NotSame(nest, restored);
+        return restored;
+    }
+
+    public void Dispose()
+    {
+        Directory.Delete(Folder, recursive: true);
+    }
+}