diff --git a/OpenNest.Data/StandardThicknesses.cs b/OpenNest.Data/StandardThicknesses.cs
new file mode 100644
index 00000000..24ebcf2b
--- /dev/null
+++ b/OpenNest.Data/StandardThicknesses.cs
@@ -0,0 +1,128 @@
+using System.Globalization;
+using System.Text.RegularExpressions;
+
+namespace OpenNest.Data;
+
+/// <summary>
+/// The sheet gauges (manufacturers' standard gauge for steel) and common plate
+/// fractions offered in thickness boxes, so an operator can pick "16 ga - 0.0598"
+/// without knowing the decimal. Typed text still accepts any decimal thickness.
+/// </summary>
+public static partial class StandardThicknesses
+{
+    /// <summary>One listed thickness: its name ("16 ga", "1/4\"") and value in inches.</summary>
+    public sealed record Entry(string Name, double Inches);
+
+    private const double MillimetersPerInch = 25.4;
+
+    private static readonly (int Gauge, double Inches)[] SteelGauges =
+    {
+        (3, 0.2391), (4, 0.2242), (5, 0.2092), (6, 0.1943), (7, 0.1793), (8, 0.1644),
+        (9, 0.1495), (10, 0.1345), (11, 0.1196), (12, 0.1046), (13, 0.0897), (14, 0.0747),
+        (15, 0.0673), (16, 0.0598), (17, 0.0538), (18, 0.0478), (19, 0.0418), (20, 0.0359),
+        (21, 0.0329), (22, 0.0299), (23, 0.0269), (24, 0.0239), (25, 0.0209), (26, 0.0179),
+    };
+
+    private static readonly string[] PlateFractions =
+    {
+        "1/16", "1/8", "3/16", "1/4", "5/16", "3/8", "7/16", "1/2", "9/16", "5/8", "11/16",
+        "3/4", "7/8", "1", "1-1/8", "1-1/4", "1-3/8", "1-1/2", "1-3/4", "2",
+    };
+
+    /// <summary>Gauges thinnest first, then plate fractions thinnest first.</summary>
+    public static IReadOnlyList<Entry> Entries { get; } = SteelGauges
+        .OrderBy(g => g.Inches)
+        .Select(g => new Entry($"{g.Gauge} ga", g.Inches))
+        .Concat(PlateFractions.Select(f => new Entry($"{f}\"", ReadInches(f) ?? 0)))
+        .ToArray();
+
+    /// <summary>The value of <paramref name="entry"/> in <paramref name="units"/>.</summary>
+    public static double ValueIn(Entry entry, Units units) =>
+        units == Units.Millimeters ? entry.Inches * MillimetersPerInch : entry.Inches;
+
+    /// <summary>The list text for <paramref name="entry"/>, e.g. "16 ga - 0.0598".</summary>
+    public static string Label(Entry entry, Units units) =>
+        $"{entry.Name} - {FormatNumber(ValueIn(entry, units), units)}";
+
+    /// <summary>
+    /// The text a thickness box shows for <paramref name="value"/>: the listed label when
+    /// it matches an entry to the displayed precision, otherwise the plain number.
+    /// </summary>
+    public static string Format(double value, Units units)
+    {
+        var entry = Find(value, units);
+        return entry != null ? Label(entry, units) : FormatNumber(value, units);
+    }
+
+    /// <summary>The entry <paramref name="value"/> matches to the displayed precision, or null.</summary>
+    public static Entry? Find(double value, Units units)
+    {
+        var tolerance = units == Units.Millimeters ? 0.0005 : 0.00005;
+        return Entries.FirstOrDefault(e => System.Math.Abs(ValueIn(e, units) - value) < tolerance);
+    }
+
+    /// <summary>
+    /// Reads a thickness box: a list label, a gauge ("16 ga", "16ga", "#16"), a fraction of
+    /// an inch ("3/32", "1-1/4", "1 1/4\"") or a non-negative number. Blank text reads as 0.
+    /// </summary>
+    public static bool TryParse(string? text, Units units, out double value)
+    {
+        value = 0;
+        var trimmed = (text ?? "").Trim();
+        if (trimmed.Length == 0)
+            return true;
+
+        var entry = Entries.FirstOrDefault(e =>
+            string.Equals(Label(e, units), trimmed, StringComparison.OrdinalIgnoreCase));
+
+        var gauge = GaugePattern().Match(trimmed);
+        if (entry == null && gauge.Success)
+            entry = Entries.FirstOrDefault(e => e.Name == $"{gauge.Groups["g"].Value} ga");
+
+        if (entry != null)
+        {
+            value = ValueIn(entry, units);
+            return true;
+        }
+
+        if (gauge.Success)
+            return false;
+
+        // Fractions are always inches, converted for a millimeter box.
+        if (trimmed.Contains('/'))
+        {
+            if (ReadInches(trimmed) is not double inches)
+                return false;
+            value = units == Units.Millimeters ? inches * MillimetersPerInch : inches;
+            return true;
+        }
+
+        return double.TryParse(trimmed, NumberStyles.Float, CultureInfo.CurrentCulture, out value)
+            && double.IsFinite(value) && value >= 0;
+    }
+
+    private static string FormatNumber(double value, Units units) =>
+        value.ToString(units == Units.Millimeters ? "0.###" : "0.####", CultureInfo.CurrentCulture);
+
+    /// <summary>Reads "3/16", "1-1/4" or "1 1/4\"" as inches; null when not a fraction.</summary>
+    private static double? ReadInches(string text)
+    {
+        var match = FractionPattern().Match(text.Trim());
+        if (!match.Success)
+            return null;
+
+        var whole = match.Groups["w"].Success ? int.Parse(match.Groups["w"].Value, CultureInfo.InvariantCulture) : 0;
+        if (!match.Groups["n"].Success)
+            return whole;
+
+        var numerator = int.Parse(match.Groups["n"].Value, CultureInfo.InvariantCulture);
+        var denominator = int.Parse(match.Groups["d"].Value, CultureInfo.InvariantCulture);
+        return denominator == 0 ? null : whole + (double)numerator / denominator;
+    }
+
+    [GeneratedRegex(@"^(?:(?<w>\d{1,3})(?:[\s-]+(?<n>\d{1,4})/(?<d>\d{1,4}))?|(?<n>\d{1,4})/(?<d>\d{1,4}))\s*""?$")]
+    private static partial Regex FractionPattern();
+
+    [GeneratedRegex(@"^(?:#\s*(?<g>\d+)|(?<g>\d+)\s*(?:ga|gauge|gage)\.?)$", RegexOptions.IgnoreCase)]
+    private static partial Regex GaugePattern();
+}
diff --git a/OpenNest.Tests/Data/StandardThicknessesTests.cs b/OpenNest.Tests/Data/StandardThicknessesTests.cs
new file mode 100644
index 00000000..00bda892
--- /dev/null
+++ b/OpenNest.Tests/Data/StandardThicknessesTests.cs
@@ -0,0 +1,72 @@
+using OpenNest.Data;
+
+namespace OpenNest.Tests.Data;
+
+/// <summary>
+/// The thickness box list: gauges and plate fractions read and display as their
+/// decimals, and any other typed decimal still works.
+/// </summary>
+public class StandardThicknessesTests
+{
+    [Theory]
+    [InlineData("16 ga - 0.0598", 0.0598)]
+    [InlineData("16 ga", 0.0598)]
+    [InlineData("16GA", 0.0598)]
+    [InlineData("16 gauge", 0.0598)]
+    [InlineData("#10", 0.1345)]
+    [InlineData("1/4", 0.25)]
+    [InlineData("1/4\"", 0.25)]
+    [InlineData("3/32", 0.09375)]
+    [InlineData("1-1/4", 1.25)]
+    [InlineData("1 1/4\"", 1.25)]
+    [InlineData("1-1/2\" - 1.5", 1.5)]
+    [InlineData("0.0598", 0.0598)]
+    [InlineData("0.123", 0.123)]
+    [InlineData("", 0)]
+    public void TryParse_ReadsGaugesFractionsAndDecimals(string text, double expected)
+    {
+        Assert.True(StandardThicknesses.TryParse(text, Units.Inches, out var value));
+        Assert.Equal(expected, value, 6);
+    }
+
+    [Theory]
+    [InlineData("abc")]
+    [InlineData("99 ga")]
+    [InlineData("-0.1")]
+    [InlineData("1/0")]
+    [InlineData("1/")]
+    public void TryParse_RejectsUnknownText(string text) =>
+        Assert.False(StandardThicknesses.TryParse(text, Units.Inches, out _));
+
+    [Fact]
+    public void Format_ShowsTheGaugeForAMatchingDecimal()
+    {
+        Assert.Equal("16 ga - 0.0598", StandardThicknesses.Format(0.0598, Units.Inches));
+        Assert.Equal("1/4\" - 0.25", StandardThicknesses.Format(0.25, Units.Inches));
+        Assert.Equal("1-1/4\" - 1.25", StandardThicknesses.Format(1.25, Units.Inches));
+        Assert.Equal("0.123", StandardThicknesses.Format(0.123, Units.Inches));
+    }
+
+    [Fact]
+    public void Millimeters_ListAndReadMetricValues()
+    {
+        Assert.Equal("16 ga - 1.519", StandardThicknesses.Format(0.0598 * 25.4, Units.Millimeters));
+        Assert.True(StandardThicknesses.TryParse("16 ga", Units.Millimeters, out var value));
+        Assert.Equal(1.51892, value, 5);
+        Assert.True(StandardThicknesses.TryParse("3/32", Units.Millimeters, out value));
+        Assert.Equal(2.38125, value, 5);
+    }
+
+    [Fact]
+    public void Entries_ListGaugesThenFractions_ThinnestFirst()
+    {
+        var gauges = StandardThicknesses.Entries.TakeWhile(e => e.Name.EndsWith(" ga")).ToList();
+        Assert.Equal("26 ga", gauges[0].Name);
+        Assert.Equal("3 ga", gauges[^1].Name);
+        Assert.Equal(gauges.OrderBy(e => e.Inches), gauges);
+        var fractions = StandardThicknesses.Entries.Skip(gauges.Count).ToList();
+        Assert.Equal(("1/16\"", 0.0625), (fractions[0].Name, fractions[0].Inches));
+        Assert.Equal(("2\"", 2.0), (fractions[^1].Name, fractions[^1].Inches));
+        Assert.Equal(fractions.OrderBy(e => e.Inches), fractions);
+    }
+}
diff --git a/OpenNest.WinForms.Tests/Forms/EditNestInfoFormTests.cs b/OpenNest.WinForms.Tests/Forms/EditNestInfoFormTests.cs
index fc704ef6..1f2be4a1 100644
--- a/OpenNest.WinForms.Tests/Forms/EditNestInfoFormTests.cs
+++ b/OpenNest.WinForms.Tests/Forms/EditNestInfoFormTests.cs
@@ -49,6 +49,31 @@ public class EditNestInfoFormTests
         });
     }
 
+    [Fact]
+    public void ThicknessBox_ReadsAPickedGauge_AndRejectsUnreadableText()
+    {
+        RunSta(() =>
+        {
+            using var form = new EditNestInfoForm();
+            var nest = AcceptanceNest();
+            form.LoadNestInfo(nest);
+            var thickness = (OpenNest.Controls.ThicknessComboBox)form.Controls.Find("thicknessBox", true).Single();
+            var apply = form.Controls.Find("applyButton", true).Single();
+
+            Assert.Equal("1/4\" - 0.25", thickness.Text);
+            thickness.SelectedItem = "16 ga - 0.0598";
+            Assert.Equal(0.0598, form.Thickness);
+            Assert.True(apply.Enabled);
+
+            thickness.Text = "sixteen";
+            Assert.False(apply.Enabled);
+
+            thickness.Text = "16ga";
+            form.SaveNestInfo(nest);
+            Assert.Equal(0.0598, nest.Thickness);
+        });
+    }
+
     private static Nest AcceptanceNest()
     {
         var nest = new Nest("Acceptance nest")
diff --git a/OpenNest.WinForms.Tests/Forms/SaveToDrawingLibraryFormTests.cs b/OpenNest.WinForms.Tests/Forms/SaveToDrawingLibraryFormTests.cs
index d4613f39..60c99dfa 100644
--- a/OpenNest.WinForms.Tests/Forms/SaveToDrawingLibraryFormTests.cs
+++ b/OpenNest.WinForms.Tests/Forms/SaveToDrawingLibraryFormTests.cs
@@ -30,7 +30,7 @@ public class SaveToDrawingLibraryFormTests
                 Assert.Equal("SYN-101", Field<TextBox>(form, "nameBox").Text);
                 Assert.Equal("Synthetic Steel", Field<ComboBox>(form, "materialBox").Text);
                 Assert.Equal("Grade A", Field<TextBox>(form, "gradeBox").Text);
-                Assert.Equal(0.25m, Field<NumericUpDown>(form, "thicknessBox").Value);
+                Assert.Equal("1/4\" - 0.25", Field<OpenNest.Controls.ThicknessComboBox>(form, "thicknessBox").Text);
                 Assert.Equal(CutType.Waterjet, Field<ComboBox>(form, "cutTypeBox").SelectedItem);
                 PumpUntil(() => save.Enabled, "the duplicate check");
                 Assert.Equal("Create a separate library drawing", saveAs.Text);
@@ -62,18 +62,18 @@ public class SaveToDrawingLibraryFormTests
                 form.Show();
                 var saveAs = Field<ComboBox>(form, "saveAsBox");
                 var save = Field<Button>(form, "saveButton");
-                var thickness = Field<NumericUpDown>(form, "thicknessBox");
+                var thickness = Field<OpenNest.Controls.ThicknessComboBox>(form, "thicknessBox");
 
                 PumpUntil(() => save.Enabled, "the duplicate check");
                 Assert.StartsWith("Revision 2 of 'SYN-101'", saveAs.Text);
 
-                thickness.Value = 0.1875m;
+                thickness.Value = 0.1875;
                 Assert.False(save.Enabled);
                 Assert.Equal(-1, saveAs.SelectedIndex);
                 PumpUntil(() => save.Enabled, "the second duplicate check");
                 Assert.Equal("Create a separate library drawing", saveAs.Text);
 
-                thickness.Value = 0.25m;
+                thickness.Value = 0.25;
                 PumpUntil(() => save.Enabled, "the third duplicate check");
                 Run(form.SaveAsync());
 
diff --git a/OpenNest/Controls/ThicknessComboBox.cs b/OpenNest/Controls/ThicknessComboBox.cs
new file mode 100644
index 00000000..84745af3
--- /dev/null
+++ b/OpenNest/Controls/ThicknessComboBox.cs
@@ -0,0 +1,81 @@
+using System;
+using System.ComponentModel;
+using System.Windows.Forms;
+using OpenNest.Data;
+
+namespace OpenNest.Controls
+{
+    /// <summary>
+    /// A thickness box that lists the standard gauges and plate fractions ("16 ga - 0.0598")
+    /// for the current units while still accepting any typed decimal. See
+    /// <see cref="StandardThicknesses"/> for the accepted text.
+    /// </summary>
+    public class ThicknessComboBox : ComboBox
+    {
+        private Units units = Units.Inches;
+
+        public ThicknessComboBox()
+        {
+            DropDownStyle = ComboBoxStyle.DropDown;
+            MaxDropDownItems = 16;
+            FillItems();
+        }
+
+        /// <summary>The units the listed values and typed numbers are in.</summary>
+        [DefaultValue(Units.Inches)]
+        public Units Units
+        {
+            get { return units; }
+            set
+            {
+                if (units == value)
+                    return;
+
+                // The thickness keeps its number; only the listed values change units.
+                var valid = TryGetValue(out var current);
+                units = value;
+                FillItems();
+                if (valid)
+                    Value = current;
+            }
+        }
+
+        /// <summary>True when the text reads as a thickness.</summary>
+        [Browsable(false)]
+        public bool IsValid => TryGetValue(out _);
+
+        /// <summary>The thickness in <see cref="Units"/>; 0 when blank or unreadable.</summary>
+        [Browsable(false)]
+        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
+        public double Value
+        {
+            get { return TryGetValue(out var value) ? value : 0; }
+            set { Text = StandardThicknesses.Format(value, units); }
+        }
+
+        public bool TryGetValue(out double value) => StandardThicknesses.TryParse(Text, units, out value);
+
+        protected override void OnEnter(EventArgs e)
+        {
+            base.OnEnter(e);
+            SelectAll();
+        }
+
+        protected override void OnLeave(EventArgs e)
+        {
+            // Show a typed gauge or matching decimal as its listed label.
+            if (TryGetValue(out var value) && Text.Trim().Length > 0)
+                Value = value;
+            base.OnLeave(e);
+        }
+
+        private void FillItems()
+        {
+            var text = Text;
+            Items.Clear();
+            foreach (var entry in StandardThicknesses.Entries)
+                Items.Add(StandardThicknesses.Label(entry, units));
+            Text = text;
+        }
+    }
+}
diff --git a/OpenNest/Forms/EditNestInfoForm.Designer.cs b/OpenNest/Forms/EditNestInfoForm.Designer.cs
index 7f0aac23..bdbebc20 100644
--- a/OpenNest/Forms/EditNestInfoForm.Designer.cs
+++ b/OpenNest/Forms/EditNestInfoForm.Designer.cs
@@ -55,7 +55,7 @@
             this.radioButton1 = new System.Windows.Forms.RadioButton();
             this.radioButton2 = new System.Windows.Forms.RadioButton();
             this.label2 = new System.Windows.Forms.Label();
-            this.thicknessBox = new OpenNest.Controls.NumericUpDown();
+            this.thicknessBox = new OpenNest.Controls.ThicknessComboBox();
             this.label3 = new System.Windows.Forms.Label();
             this.label4 = new System.Windows.Forms.Label();
             this.customerBox = new System.Windows.Forms.TextBox();
@@ -90,7 +90,6 @@
             this.tabPage1.SuspendLayout();
             this.tableLayoutPanel3.SuspendLayout();
             this.tableLayoutPanel4.SuspendLayout();
-            ((System.ComponentModel.ISupportInitialize)(this.thicknessBox)).BeginInit();
             this.tabPage2.SuspendLayout();
             this.tabPage3.SuspendLayout();
             this.bottomPanel1.SuspendLayout();
@@ -502,21 +501,10 @@
             // thicknessBox
             // 
             this.thicknessBox.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Left | System.Windows.Forms.AnchorStyles.Right)));
-            this.thicknessBox.DecimalPlaces = 4;
-            this.thicknessBox.Increment = new decimal(new int[] {
-            25,
-            0,
-            0,
-            131072});
             this.thicknessBox.Location = new System.Drawing.Point(135, 125);
-            this.thicknessBox.Maximum = new decimal(new int[] {
-            999999,
-            0,
-            0,
-            0});
             this.thicknessBox.Name = "thicknessBox";
             this.thicknessBox.Size = new System.Drawing.Size(224, 22);
-            this.thicknessBox.Suffix = "";
+            this.thicknessBox.FormattingEnabled = true;
             this.thicknessBox.TabIndex = 7;
             //
             // labelMaterial
@@ -753,7 +741,6 @@
             this.tableLayoutPanel3.PerformLayout();
             this.tableLayoutPanel4.ResumeLayout(false);
             this.tableLayoutPanel4.PerformLayout();
-            ((System.ComponentModel.ISupportInitialize)(this.thicknessBox)).EndInit();
             this.tabPage2.ResumeLayout(false);
             this.tabPage3.ResumeLayout(false);
             this.tabPage3.PerformLayout();
@@ -779,7 +766,7 @@
         private System.Windows.Forms.TableLayoutPanel tableLayoutPanel1;
         private System.Windows.Forms.Label labelSize;
         private System.Windows.Forms.TextBox sizeBox;
-        private Controls.NumericUpDown thicknessBox;
+        private Controls.ThicknessComboBox thicknessBox;
         private System.Windows.Forms.Label labelThk;
         private System.Windows.Forms.Label labelPartSpacing;
         private Controls.NumericUpDown partSpacingBox;
diff --git a/OpenNest/Forms/EditNestInfoForm.cs b/OpenNest/Forms/EditNestInfoForm.cs
index afe0ff3d..9fc517a9 100644
--- a/OpenNest/Forms/EditNestInfoForm.cs
+++ b/OpenNest/Forms/EditNestInfoForm.cs
@@ -38,6 +38,7 @@ namespace OpenNest.Forms
             };
             Disposed += (sender, e) => timer.Dispose();
             nameBox.TextChanged += (sender, e) => EnableCheck();
+            thicknessBox.TextChanged += (sender, e) => EnableCheck();
             materialBox.TextChanged += (sender, e) => RefreshGrades();
             EnableCheck();
         }
@@ -137,8 +138,8 @@ namespace OpenNest.Forms
 
         public double Thickness
         {
-            get { return (double)thicknessBox.Value; }
-            set { thicknessBox.Value = (decimal)value; }
+            get { return thicknessBox.Value; }
+            set { thicknessBox.Value = value; }
         }
 
         public string MaterialName
@@ -241,7 +242,6 @@ namespace OpenNest.Forms
         {
             var unitBoxes = new Controls.NumericUpDown[]
             {
-                thicknessBox,
                 partSpacingBox,
                 leftSpacingBox,
                 topSpacingBox,
@@ -253,6 +253,8 @@ namespace OpenNest.Forms
 
             foreach (var box in unitBoxes)
                 box.Suffix = unitString;
+
+            thicknessBox.Units = GetUnits();
         }
 
         public int Quadrant
@@ -271,6 +273,12 @@ namespace OpenNest.Forms
                 return;
             }
 
+            if (!thicknessBox.IsValid)
+            {
+                applyButton.Enabled = false;
+                return;
+            }
+
             if (!OpenNest.Geometry.Size.TryParse(sizeBox.Text, out size))
             {
                 applyButton.Enabled = false;
diff --git a/OpenNest/Forms/SaveToDrawingLibraryForm.Designer.cs b/OpenNest/Forms/SaveToDrawingLibraryForm.Designer.cs
index c4192e3f..dc3a97ad 100644
--- a/OpenNest/Forms/SaveToDrawingLibraryForm.Designer.cs
+++ b/OpenNest/Forms/SaveToDrawingLibraryForm.Designer.cs
@@ -28,7 +28,7 @@ namespace OpenNest.Forms
             gradeLabel = new System.Windows.Forms.Label();
             gradeBox = new System.Windows.Forms.TextBox();
             thicknessLabel = new System.Windows.Forms.Label();
-            thicknessBox = new System.Windows.Forms.NumericUpDown();
+            thicknessBox = new OpenNest.Controls.ThicknessComboBox();
             cutTypeLabel = new System.Windows.Forms.Label();
             cutTypeBox = new System.Windows.Forms.ComboBox();
             notesLabel = new System.Windows.Forms.Label();
@@ -44,7 +44,6 @@ namespace OpenNest.Forms
             saveButton = new System.Windows.Forms.Button();
             lookupTimer = new System.Windows.Forms.Timer(components);
             layoutTable.SuspendLayout();
-            ((System.ComponentModel.ISupportInitialize)thicknessBox).BeginInit();
             buttonPanel.SuspendLayout();
             SuspendLayout();
             //
@@ -172,14 +171,10 @@ namespace OpenNest.Forms
             // thicknessBox
             //
             thicknessBox.Anchor = System.Windows.Forms.AnchorStyles.Left;
-            thicknessBox.DecimalPlaces = 4;
-            thicknessBox.Increment = new decimal(new int[] { 1, 0, 0, 131072 });
-            thicknessBox.Maximum = new decimal(new int[] { 10000, 0, 0, 0 });
             thicknessBox.Name = "thicknessBox";
-            thicknessBox.Size = new System.Drawing.Size(100, 25);
+            thicknessBox.Size = new System.Drawing.Size(160, 25);
             thicknessBox.TabIndex = 9;
-            thicknessBox.TextAlign = System.Windows.Forms.HorizontalAlignment.Right;
-            thicknessBox.ValueChanged += Details_Changed;
+            thicknessBox.TextChanged += Details_Changed;
             //
             // cutTypeLabel
             //
@@ -321,7 +316,6 @@ namespace OpenNest.Forms
             Shown += SaveToDrawingLibraryForm_Shown;
             layoutTable.ResumeLayout(false);
             layoutTable.PerformLayout();
-            ((System.ComponentModel.ISupportInitialize)thicknessBox).EndInit();
             buttonPanel.ResumeLayout(false);
             buttonPanel.PerformLayout();
             ResumeLayout(false);
@@ -339,7 +333,7 @@ namespace OpenNest.Forms
         private System.Windows.Forms.Label gradeLabel;
         private System.Windows.Forms.TextBox gradeBox;
         private System.Windows.Forms.Label thicknessLabel;
-        private System.Windows.Forms.NumericUpDown thicknessBox;
+        private OpenNest.Controls.ThicknessComboBox thicknessBox;
         private System.Windows.Forms.Label cutTypeLabel;
         private System.Windows.Forms.ComboBox cutTypeBox;
         private System.Windows.Forms.Label notesLabel;
diff --git a/OpenNest/Forms/SaveToDrawingLibraryForm.cs b/OpenNest/Forms/SaveToDrawingLibraryForm.cs
index af6cc526..9102a5ea 100644
--- a/OpenNest/Forms/SaveToDrawingLibraryForm.cs
+++ b/OpenNest/Forms/SaveToDrawingLibraryForm.cs
@@ -53,7 +53,8 @@ namespace OpenNest.Forms
             customerBox.Text = metadata.Customer;
             materialBox.Text = metadata.MaterialName;
             gradeBox.Text = metadata.MaterialGrade;
-            thicknessBox.Value = System.Math.Min(thicknessBox.Maximum, (decimal)metadata.Thickness);
+            thicknessBox.Units = metadata.Units;
+            thicknessBox.Value = metadata.Thickness;
             thicknessLabel.Text = $"Thickness ({UnitsHelper.GetShortString(metadata.Units)}):";
             cutTypeBox.SelectedItem = metadata.CutType;
             notesBox.Text = metadata.Notes;
@@ -241,7 +242,10 @@ namespace OpenNest.Forms
             Customer = customerBox.Text.Trim(),
             MaterialName = materialBox.Text.Trim(),
             MaterialGrade = gradeBox.Text.Trim(),
-            Thickness = DrawingLibraryRules.NormalizeThickness((double)thicknessBox.Value),
+            // Unreadable text fails the metadata rules instead of reading as 0.
+            Thickness = thicknessBox.TryGetValue(out var thickness)
+                ? DrawingLibraryRules.NormalizeThickness(thickness)
+                : double.NaN,
             Units = session.Nest.Units,
             CutType = cutTypeBox.SelectedItem is CutType cutType ? cutType : CutType.Laser,
             Notes = notesBox.Text,