fix: add proper spacing between G-code words in Cincinnati post output

G-code output was concatenated without spaces (e.g. N1005G0X1.4375Y-0.6562).
Now emits standard spacing (N1005 G0 X1.4375 Y-0.6562) across all motion
commands, line numbers, kerf comp, feedrates, M-codes, and comments.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

OpenNest.Posts.Cincinnati/CincinnatiFeatureWriter.cs

@@ -19,6 +19,7 @@ public sealed class FeatureContext
     public bool IsLastFeatureOnSheet { get; set; }
     public bool IsSafetyHeadraise { get; set; }
     public bool IsExteriorFeature { get; set; }
+    public bool IsEtch { get; set; }
     public string LibraryFile { get; set; } = "";
     public double CutDistance { get; set; }
     public double SheetDiagonal { get; set; }
@@ -61,17 +62,24 @@ public sealed class CincinnatiFeatureWriter
         if (ctx.IsFirstFeatureOfPart && !string.IsNullOrEmpty(ctx.PartName))
             writer.WriteLine(CoordinateFormatter.Comment($"PART: {ctx.PartName}"));
 
-        // 3. G89 process params (if RepeatG89BeforeEachFeature)
+        // 3. G89 process params
-        if (_config.RepeatG89BeforeEachFeature && _config.ProcessParameterMode == G89Mode.LibraryFile)
+        if (_config.ProcessParameterMode == G89Mode.LibraryFile)
+        {
+            var lib = ctx.LibraryFile;
+            if (!string.IsNullOrEmpty(lib))
             {
-            var lib = !string.IsNullOrEmpty(ctx.LibraryFile) ? ctx.LibraryFile : _config.DefaultLibraryFile;
                 var speedClass = _speedClassifier.Classify(ctx.CutDistance, ctx.SheetDiagonal);
                 var cutDist = _speedClassifier.FormatCutDist(ctx.CutDistance, ctx.SheetDiagonal);
                 writer.WriteLine($"G89 P {lib} ({speedClass} {cutDist})");
             }
+            else
+            {
+                writer.WriteLine("(WARNING: No library found)");
+            }
+        }
 
-        // 4. Pierce and start cut
+        // 4. Pierce/beam on — G85 for etch (no pierce), G84 for cut
-        writer.WriteLine("G84");
+        writer.WriteLine(ctx.IsEtch ? "G85" : "G84");
 
         // 5. Anti-dive off
         if (_config.UseAntiDive)
@@ -90,20 +98,20 @@ public sealed class CincinnatiFeatureWriter
             {
                 var sb = new StringBuilder();
 
-                // Kerf compensation on first cutting move
+                // Kerf compensation on first cutting move (skip for etch)
-                if (!kerfEmitted && _config.KerfCompensation == KerfMode.ControllerSide)
+                if (!ctx.IsEtch && !kerfEmitted && _config.KerfCompensation == KerfMode.ControllerSide)
                 {
-                    sb.Append(_config.DefaultKerfSide == KerfSide.Left ? "G41" : "G42");
+                    sb.Append(_config.DefaultKerfSide == KerfSide.Left ? "G41 " : "G42 ");
                     kerfEmitted = true;
                 }
 
-                sb.Append($"G1X{_fmt.FormatCoord(linear.EndPoint.X)}Y{_fmt.FormatCoord(linear.EndPoint.Y)}");
+                sb.Append($"G1 X{_fmt.FormatCoord(linear.EndPoint.X)} Y{_fmt.FormatCoord(linear.EndPoint.Y)}");
 
-                // Feedrate
+                // Feedrate — etch always uses process feedrate
-                var feedVar = GetFeedVariable(linear.Layer);
+                var feedVar = ctx.IsEtch ? "#148" : GetFeedVariable(linear.Layer);
                 if (feedVar != lastFeedVar)
                 {
-                    sb.Append($"F{feedVar}");
+                    sb.Append($" F{feedVar}");
                     lastFeedVar = feedVar;
                 }
 
@@ -114,28 +122,30 @@ public sealed class CincinnatiFeatureWriter
             {
                 var sb = new StringBuilder();
 
-                // Kerf compensation on first cutting move
+                // Kerf compensation on first cutting move (skip for etch)
-                if (!kerfEmitted && _config.KerfCompensation == KerfMode.ControllerSide)
+                if (!ctx.IsEtch && !kerfEmitted && _config.KerfCompensation == KerfMode.ControllerSide)
                 {
-                    sb.Append(_config.DefaultKerfSide == KerfSide.Left ? "G41" : "G42");
+                    sb.Append(_config.DefaultKerfSide == KerfSide.Left ? "G41 " : "G42 ");
                     kerfEmitted = true;
                 }
 
                 // G2 = CW, G3 = CCW
                 var gCode = arc.Rotation == RotationType.CW ? "G2" : "G3";
-                sb.Append($"{gCode}X{_fmt.FormatCoord(arc.EndPoint.X)}Y{_fmt.FormatCoord(arc.EndPoint.Y)}");
+                sb.Append($"{gCode} X{_fmt.FormatCoord(arc.EndPoint.X)} Y{_fmt.FormatCoord(arc.EndPoint.Y)}");
 
                 // Convert absolute center to incremental I/J
                 var i = arc.CenterPoint.X - currentPos.X;
                 var j = arc.CenterPoint.Y - currentPos.Y;
-                sb.Append($"I{_fmt.FormatCoord(i)}J{_fmt.FormatCoord(j)}");
+                sb.Append($" I{_fmt.FormatCoord(i)} J{_fmt.FormatCoord(j)}");
 
-                // Feedrate — full circles use multiplied feedrate
+                // Feedrate — etch always uses process feedrate, cut uses layer-based
                 var isFullCircle = IsFullCircle(currentPos, arc.EndPoint);
-                var feedVar = isFullCircle ? "[#148*#128]" : GetFeedVariable(arc.Layer);
+                var feedVar = ctx.IsEtch ? "#148"
+                    : isFullCircle ? "[#148*#128]"
+                    : GetFeedVariable(arc.Layer);
                 if (feedVar != lastFeedVar)
                 {
-                    sb.Append($"F{feedVar}");
+                    sb.Append($" F{feedVar}");
                     lastFeedVar = feedVar;
                 }
 
@@ -183,9 +193,9 @@ public sealed class CincinnatiFeatureWriter
         var sb = new StringBuilder();
 
         if (_config.UseLineNumbers)
-            sb.Append($"N{featureNumber}");
+            sb.Append($"N{featureNumber} ");
 
-        sb.Append($"G0X{_fmt.FormatCoord(piercePoint.X)}Y{_fmt.FormatCoord(piercePoint.Y)}");
+        sb.Append($"G0 X{_fmt.FormatCoord(piercePoint.X)} Y{_fmt.FormatCoord(piercePoint.Y)}");
 
         writer.WriteLine(sb.ToString());
     }
@@ -194,7 +204,7 @@ public sealed class CincinnatiFeatureWriter
     {
         if (ctx.IsSafetyHeadraise && _config.SafetyHeadraiseDistance.HasValue)
         {
-            writer.WriteLine($"M47 P{_config.SafetyHeadraiseDistance.Value}(Safety Headraise)");
+            writer.WriteLine($"M47 P{_config.SafetyHeadraiseDistance.Value} (Safety Headraise)");
             return;
         }
 

OpenNest.Posts.Cincinnati/CincinnatiPartSubprogramWriter.cs

@@ -27,19 +27,22 @@ public sealed class CincinnatiPartSubprogramWriter
     /// The program coordinates must already be normalized to origin (0,0).
     /// </summary>
     public void Write(TextWriter w, Program normalizedProgram, string drawingName,
-        int subNumber, string libraryFile, double sheetDiagonal)
+        int subNumber, string cutLibrary, string etchLibrary, double sheetDiagonal)
     {
-        var features = SplitFeatures(normalizedProgram.Codes);
+        var allFeatures = SplitFeatures(normalizedProgram.Codes);
-        if (features.Count == 0)
+        if (allFeatures.Count == 0)
             return;
 
+        // Classify and order: etch features first, then cut features
+        var ordered = OrderFeatures(allFeatures);
+
         w.WriteLine("(*****************************************************)");
         w.WriteLine($":{subNumber}");
         w.WriteLine(CoordinateFormatter.Comment($"PART: {drawingName}"));
 
-        for (var i = 0; i < features.Count; i++)
+        for (var i = 0; i < ordered.Count; i++)
         {
-            var codes = features[i];
+            var (codes, isEtch) = ordered[i];
             var featureNumber = i == 0
                 ? _config.FeatureLineNumberStart
                 : 1000 + i + 1;
@@ -51,10 +54,11 @@ public sealed class CincinnatiPartSubprogramWriter
                 FeatureNumber = featureNumber,
                 PartName = drawingName,
                 IsFirstFeatureOfPart = false,
-                IsLastFeatureOnSheet = i == features.Count - 1,
+                IsLastFeatureOnSheet = i == ordered.Count - 1,
                 IsSafetyHeadraise = false,
                 IsExteriorFeature = false,
-                LibraryFile = libraryFile,
+                IsEtch = isEtch,
+                LibraryFile = isEtch ? etchLibrary : cutLibrary,
                 CutDistance = cutDistance,
                 SheetDiagonal = sheetDiagonal
             };
@@ -62,8 +66,30 @@ public sealed class CincinnatiPartSubprogramWriter
             _featureWriter.Write(w, ctx);
         }
 
-        w.WriteLine("G0X0Y0");
+        w.WriteLine("G0 X0 Y0");
-        w.WriteLine($"M99(END OF {drawingName})");
+        w.WriteLine($"M99 (END OF {drawingName})");
+    }
+
+    internal static List<(List<ICode> codes, bool isEtch)> OrderFeatures(List<List<ICode>> features)
+    {
+        var result = new List<(List<ICode>, bool)>();
+        var etch = new List<List<ICode>>();
+        var cut = new List<List<ICode>>();
+
+        foreach (var f in features)
+        {
+            if (CincinnatiSheetWriter.IsFeatureEtch(f))
+                etch.Add(f);
+            else
+                cut.Add(f);
+        }
+
+        foreach (var f in etch)
+            result.Add((f, true));
+        foreach (var f in cut)
+            result.Add((f, false));
+
+        return result;
     }
 
     /// <summary>

OpenNest.Posts.Cincinnati/CincinnatiPreambleWriter.cs

@@ -21,7 +21,9 @@ public sealed class CincinnatiPreambleWriter
     /// <summary>
     /// Writes the main program header block.
     /// </summary>
-    public void WriteMainProgram(TextWriter w, string nestName, string materialDescription, int sheetCount)
+    /// <param name="initialLibrary">Resolved G89 library file for the initial process setup.</param>
+    public void WriteMainProgram(TextWriter w, string nestName, string materialDescription,
+        int sheetCount, string initialLibrary)
     {
         w.WriteLine(CoordinateFormatter.Comment($"NEST {nestName}"));
         w.WriteLine(CoordinateFormatter.Comment($"CONFIGURATION - {_config.ConfigurationName}"));
@@ -39,8 +41,8 @@ public sealed class CincinnatiPreambleWriter
 
         w.WriteLine("M42");
 
-        if (_config.ProcessParameterMode == G89Mode.LibraryFile && !string.IsNullOrEmpty(_config.DefaultLibraryFile))
+        if (_config.ProcessParameterMode == G89Mode.LibraryFile && !string.IsNullOrEmpty(initialLibrary))
-            w.WriteLine($"G89 P {_config.DefaultLibraryFile}");
+            w.WriteLine($"G89 P {initialLibrary}");
 
         w.WriteLine($"M98 P{_config.VariableDeclarationSubprogram} (Variable Declaration)");
 
@@ -49,7 +51,7 @@ public sealed class CincinnatiPreambleWriter
         for (var i = 1; i <= sheetCount; i++)
         {
             var subNum = _config.SheetSubprogramStart + (i - 1);
-            w.WriteLine($"N{i}M98 P{subNum} (SHEET {i})");
+            w.WriteLine($"N{i} M98 P{subNum} (SHEET {i})");
         }
 
         w.WriteLine("M42");

OpenNest.Posts.Cincinnati/CincinnatiSheetWriter.cs

@@ -30,11 +30,14 @@ public sealed class CincinnatiSheetWriter
     /// <summary>
     /// Writes a complete sheet subprogram for the given plate.
     /// </summary>
+    /// <param name="cutLibrary">Resolved G89 library file for cut operations.</param>
+    /// <param name="etchLibrary">Resolved G89 library file for etch operations.</param>
     /// <param name="partSubprograms">
     /// Optional mapping of (drawingId, rotationKey) to sub-program number.
     /// When provided, non-cutoff parts are emitted as M98 calls instead of inline features.
     /// </param>
     public void Write(TextWriter w, Plate plate, string nestName, int sheetIndex, int subNumber,
+        string cutLibrary, string etchLibrary,
         Dictionary<(int, long), int> partSubprograms = null)
     {
         if (plate.Parts.Count == 0)
@@ -43,7 +46,6 @@ public sealed class CincinnatiSheetWriter
         var width = plate.Size.Width;
         var length = plate.Size.Length;
         var sheetDiagonal = System.Math.Sqrt(width * width + length * length);
-        var libraryFile = _config.DefaultLibraryFile ?? "";
         var varDeclSub = _config.VariableDeclarationSubprogram;
         var partCount = plate.Parts.Count(p => !p.BaseDrawing.IsCutOff);
 
@@ -55,20 +57,20 @@ public sealed class CincinnatiSheetWriter
         w.WriteLine($"( Layout {sheetIndex} )");
         w.WriteLine($"( SHEET NAME = {_fmt.FormatCoord(length)} X {_fmt.FormatCoord(width)} )");
         w.WriteLine($"( Total parts on sheet = {partCount} )");
-        w.WriteLine($"#{_config.SheetWidthVariable}={_fmt.FormatCoord(width)}(SHEET WIDTH FOR CUTOFFS)");
+        w.WriteLine($"#{_config.SheetWidthVariable}={_fmt.FormatCoord(width)} (SHEET WIDTH FOR CUTOFFS)");
-        w.WriteLine($"#{_config.SheetLengthVariable}={_fmt.FormatCoord(length)}(SHEET LENGTH FOR CUTOFFS)");
+        w.WriteLine($"#{_config.SheetLengthVariable}={_fmt.FormatCoord(length)} (SHEET LENGTH FOR CUTOFFS)");
 
         // 2. Coordinate setup
         w.WriteLine("M42");
         w.WriteLine("N10000");
-        w.WriteLine("G92X#5021Y#5022");
+        w.WriteLine("G92 X#5021 Y#5022");
-        if (!string.IsNullOrEmpty(libraryFile))
+        if (!string.IsNullOrEmpty(cutLibrary))
-            w.WriteLine($"G89 P {libraryFile}");
+            w.WriteLine($"G89 P {cutLibrary}");
         w.WriteLine($"M98 P{varDeclSub} (Variable Declaration)");
         w.WriteLine("G90");
-        w.WriteLine("M47(CPT)");
+        w.WriteLine("M47");
-        if (!string.IsNullOrEmpty(libraryFile))
+        if (!string.IsNullOrEmpty(cutLibrary))
-            w.WriteLine($"G89 P {libraryFile}");
+            w.WriteLine($"G89 P {cutLibrary}");
         w.WriteLine("GOTO1( Goto Feature )");
 
         // 3. Order parts: non-cutoff sorted by Bottom then Left, cutoffs last
@@ -86,20 +88,20 @@ public sealed class CincinnatiSheetWriter
 
         // 4. Emit parts
         if (partSubprograms != null)
-            WritePartsWithSubprograms(w, allParts, libraryFile, sheetDiagonal, partSubprograms);
+            WritePartsWithSubprograms(w, allParts, cutLibrary, etchLibrary, sheetDiagonal, partSubprograms);
         else
-            WritePartsInline(w, allParts, libraryFile, sheetDiagonal);
+            WritePartsInline(w, allParts, cutLibrary, etchLibrary, sheetDiagonal);
 
         // 5. Footer
         w.WriteLine("M42");
-        w.WriteLine("G0X0Y0");
+        w.WriteLine("G0 X0 Y0");
         if (_config.PalletExchange != PalletMode.None)
-            w.WriteLine($"N{sheetIndex + 1}M50");
+            w.WriteLine($"N{sheetIndex + 1} M50");
-        w.WriteLine($"M99(END OF {nestName}.{sheetIndex:D3})");
+        w.WriteLine($"M99 (END OF {nestName}.{sheetIndex:D3})");
     }
 
     private void WritePartsWithSubprograms(TextWriter w, List<Part> allParts,
-        string libraryFile, double sheetDiagonal,
+        string cutLibrary, string etchLibrary, double sheetDiagonal,
         Dictionary<(int, long), int> partSubprograms)
     {
         var lastPartName = "";
@@ -126,26 +128,28 @@ public sealed class CincinnatiSheetWriter
             else
             {
                 // Inline features for cutoffs or parts without sub-programs
-                var features = SplitPartFeatures(part);
+                var features = SplitAndOrderFeatures(part);
                 for (var f = 0; f < features.Count; f++)
                 {
+                    var (codes, isEtch) = features[f];
                     var featureNumber = featureIndex == 0
                         ? _config.FeatureLineNumberStart
                         : 1000 + featureIndex + 1;
 
                     var isLastFeature = isLastPart && f == features.Count - 1;
-                    var cutDistance = ComputeCutDistance(features[f]);
+                    var cutDistance = ComputeCutDistance(codes);
 
                     var ctx = new FeatureContext
                     {
-                        Codes = features[f],
+                        Codes = codes,
                         FeatureNumber = featureNumber,
                         PartName = partName,
                         IsFirstFeatureOfPart = isNewPart && f == 0,
                         IsLastFeatureOnSheet = isLastFeature,
                         IsSafetyHeadraise = isSafetyHeadraise && f == 0,
                         IsExteriorFeature = false,
-                        LibraryFile = libraryFile,
+                        IsEtch = isEtch,
+                        LibraryFile = isEtch ? etchLibrary : cutLibrary,
                         CutDistance = cutDistance,
                         SheetDiagonal = sheetDiagonal
                     };
@@ -164,7 +168,7 @@ public sealed class CincinnatiSheetWriter
     {
         // Safety headraise before rapid to new part
         if (isSafetyHeadraise && _config.SafetyHeadraiseDistance.HasValue)
-            w.WriteLine($"M47 P{_config.SafetyHeadraiseDistance.Value}(Safety Headraise)");
+            w.WriteLine($"M47 P{_config.SafetyHeadraiseDistance.Value} (Safety Headraise)");
 
         // Rapid to part position (bounding box lower-left)
         var featureNumber = featureIndex == 0
@@ -173,21 +177,21 @@ public sealed class CincinnatiSheetWriter
 
         var sb = new StringBuilder();
         if (_config.UseLineNumbers)
-            sb.Append($"N{featureNumber}");
+            sb.Append($"N{featureNumber} ");
-        sb.Append($"G0X{_fmt.FormatCoord(part.Left)}Y{_fmt.FormatCoord(part.Bottom)}");
+        sb.Append($"G0 X{_fmt.FormatCoord(part.Left)} Y{_fmt.FormatCoord(part.Bottom)}");
         w.WriteLine(sb.ToString());
 
         // Part name comment
         w.WriteLine(CoordinateFormatter.Comment($"PART: {partName}"));
 
         // Set local coordinate system at part position
-        w.WriteLine("G92X0Y0");
+        w.WriteLine("G92 X0 Y0");
 
         // Call part sub-program
-        w.WriteLine($"M98P{subNum}({partName})");
+        w.WriteLine($"M98 P{subNum} ({partName})");
 
         // Restore sheet coordinate system
-        w.WriteLine($"G92X{_fmt.FormatCoord(part.Left)}Y{_fmt.FormatCoord(part.Bottom)}");
+        w.WriteLine($"G92 X{_fmt.FormatCoord(part.Left)} Y{_fmt.FormatCoord(part.Bottom)}");
 
         // Head raise (unless last part on sheet)
         if (!isLastPart)
@@ -195,36 +199,22 @@ public sealed class CincinnatiSheetWriter
     }
 
     private void WritePartsInline(TextWriter w, List<Part> allParts,
-        string libraryFile, double sheetDiagonal)
+        string cutLibrary, string etchLibrary, double sheetDiagonal)
     {
-        // Multi-contour splitting
+        // Split and classify features, ordering etch before cut per part
-        var features = new List<(Part part, List<ICode> codes)>();
+        var features = new List<(Part part, List<ICode> codes, bool isEtch)>();
         foreach (var part in allParts)
         {
-            List<ICode> current = null;
+            var partFeatures = SplitAndOrderFeatures(part);
-            foreach (var code in part.Program.Codes)
+            foreach (var (codes, isEtch) in partFeatures)
-            {
+                features.Add((part, codes, isEtch));
-                if (code is RapidMove)
-                {
-                    if (current != null)
-                        features.Add((part, current));
-                    current = new List<ICode> { code };
-                }
-                else
-                {
-                    current ??= new List<ICode>();
-                    current.Add(code);
-                }
-            }
-            if (current != null && current.Count > 0)
-                features.Add((part, current));
         }
 
         // Emit features
         var lastPartName = "";
         for (var i = 0; i < features.Count; i++)
         {
-            var (part, codes) = features[i];
+            var (part, codes, isEtch) = features[i];
             var partName = part.BaseDrawing.Name;
             var isFirstFeatureOfPart = partName != lastPartName;
             var isSafetyHeadraise = partName != lastPartName && lastPartName != "";
@@ -245,7 +235,8 @@ public sealed class CincinnatiSheetWriter
                 IsLastFeatureOnSheet = isLastFeature,
                 IsSafetyHeadraise = isSafetyHeadraise,
                 IsExteriorFeature = false,
-                LibraryFile = libraryFile,
+                IsEtch = isEtch,
+                LibraryFile = isEtch ? etchLibrary : cutLibrary,
                 CutDistance = cutDistance,
                 SheetDiagonal = sheetDiagonal
             };
@@ -255,9 +246,14 @@ public sealed class CincinnatiSheetWriter
         }
     }
 
-    private static List<List<ICode>> SplitPartFeatures(Part part)
+    /// <summary>
+    /// Splits a part's program into features (by rapids), classifies each as etch or cut,
+    /// and orders etch features before cut features.
+    /// </summary>
+    public static List<(List<ICode> codes, bool isEtch)> SplitAndOrderFeatures(Part part)
     {
-        var features = new List<List<ICode>>();
+        var etchFeatures = new List<List<ICode>>();
+        var cutFeatures = new List<List<ICode>>();
         List<ICode> current = null;
 
         foreach (var code in part.Program.Codes)
@@ -265,7 +261,7 @@ public sealed class CincinnatiSheetWriter
             if (code is RapidMove)
             {
                 if (current != null)
-                    features.Add(current);
+                    ClassifyAndAdd(current, etchFeatures, cutFeatures);
                 current = new List<ICode> { code };
             }
             else
@@ -276,9 +272,40 @@ public sealed class CincinnatiSheetWriter
         }
 
         if (current != null && current.Count > 0)
-            features.Add(current);
+            ClassifyAndAdd(current, etchFeatures, cutFeatures);
 
-        return features;
+        // Etch features first, then cut features
+        var result = new List<(List<ICode>, bool)>();
+        foreach (var f in etchFeatures)
+            result.Add((f, true));
+        foreach (var f in cutFeatures)
+            result.Add((f, false));
+
+        return result;
+    }
+
+    private static void ClassifyAndAdd(List<ICode> codes,
+        List<List<ICode>> etchFeatures, List<List<ICode>> cutFeatures)
+    {
+        if (IsFeatureEtch(codes))
+            etchFeatures.Add(codes);
+        else
+            cutFeatures.Add(codes);
+    }
+
+    /// <summary>
+    /// A feature is etch if any non-rapid move has LayerType.Scribe.
+    /// </summary>
+    public static bool IsFeatureEtch(List<ICode> codes)
+    {
+        foreach (var code in codes)
+        {
+            if (code is LinearMove linear && linear.Layer == LayerType.Scribe)
+                return true;
+            if (code is ArcMove arc && arc.Layer == LayerType.Scribe)
+                return true;
+        }
+        return false;
     }
 
     private static double ComputeCutDistance(List<ICode> codes)

OpenNest.Tests/Cincinnati/CincinnatiFeatureWriterTests.cs

@@ -13,9 +13,7 @@ public class CincinnatiFeatureWriterTests
         UseAntiDive = true,
         KerfCompensation = KerfMode.ControllerSide,
         DefaultKerfSide = KerfSide.Left,
-        RepeatG89BeforeEachFeature = true,
         ProcessParameterMode = G89Mode.LibraryFile,
-        DefaultLibraryFile = "MILD10",
         InteriorM47 = M47Mode.Always,
         ExteriorM47 = M47Mode.Always,
         UseSpeedGas = false,
@@ -58,7 +56,7 @@ public class CincinnatiFeatureWriterTests
         var output = WriteFeature(config, ctx);
         var lines = output.Split(Environment.NewLine, StringSplitOptions.RemoveEmptyEntries);
 
-        Assert.StartsWith("N1G0X13.401Y57.4895", lines[0]);
+        Assert.StartsWith("N1 G0 X13.401 Y57.4895", lines[0]);
     }
 
     [Fact]
@@ -70,7 +68,7 @@ public class CincinnatiFeatureWriterTests
         var output = WriteFeature(config, ctx);
         var lines = output.Split(Environment.NewLine, StringSplitOptions.RemoveEmptyEntries);
 
-        Assert.StartsWith("G0X13.401Y57.4895", lines[0]);
+        Assert.StartsWith("G0 X13.401 Y57.4895", lines[0]);
     }
 
     [Fact]
@@ -260,8 +258,8 @@ public class CincinnatiFeatureWriterTests
         var cwOutput = WriteFeature(config, SimpleContext(cwCodes));
         var ccwOutput = WriteFeature(config, SimpleContext(ccwCodes));
 
-        Assert.Contains("G2X", cwOutput);
+        Assert.Contains("G2 X", cwOutput);
-        Assert.Contains("G3X", ccwOutput);
+        Assert.Contains("G3 X", ccwOutput);
     }
 
     [Fact]
@@ -289,12 +287,10 @@ public class CincinnatiFeatureWriterTests
     }
 
     [Fact]
-    public void G89_EmittedWhenRepeatEnabled()
+    public void G89_EmittedWithLibraryFile()
     {
         var config = DefaultConfig();
-        config.RepeatG89BeforeEachFeature = true;
         config.ProcessParameterMode = G89Mode.LibraryFile;
-        config.DefaultLibraryFile = "MILD10";
         var ctx = SimpleContext();
         ctx.LibraryFile = "MILD10";
         ctx.CutDistance = 18.0;
@@ -305,14 +301,65 @@ public class CincinnatiFeatureWriterTests
     }
 
     [Fact]
-    public void G89_NotEmittedWhenRepeatDisabled()
+    public void G89_WarningEmittedWhenNoLibrary()
     {
         var config = DefaultConfig();
-        config.RepeatG89BeforeEachFeature = false;
+        config.ProcessParameterMode = G89Mode.LibraryFile;
         var ctx = SimpleContext();
+        ctx.LibraryFile = "";
         var output = WriteFeature(config, ctx);
 
-        Assert.DoesNotContain("G89", output);
+        Assert.Contains("WARNING: No library found", output);
+        Assert.DoesNotContain("G89 P", output);
+    }
+
+    [Fact]
+    public void Etch_UsesG85InsteadOfG84()
+    {
+        var config = DefaultConfig();
+        var ctx = SimpleContext();
+        ctx.IsEtch = true;
+        ctx.LibraryFile = "EtchN2.lib";
+        var output = WriteFeature(config, ctx);
+
+        Assert.Contains("G85", output);
+        Assert.DoesNotContain("G84", output);
+    }
+
+    [Fact]
+    public void Etch_SkipsKerfCompensation()
+    {
+        var config = DefaultConfig();
+        config.KerfCompensation = KerfMode.ControllerSide;
+        var ctx = SimpleContext();
+        ctx.IsEtch = true;
+        ctx.LibraryFile = "EtchN2.lib";
+        var output = WriteFeature(config, ctx);
+
+        Assert.DoesNotContain("G41", output);
+        Assert.DoesNotContain("G42", output);
+        Assert.DoesNotContain("G40", output);
+    }
+
+    [Fact]
+    public void Etch_AllMovesUseProcessFeedrate()
+    {
+        var config = DefaultConfig();
+        config.KerfCompensation = KerfMode.PreApplied;
+        var codes = new List<ICode>
+        {
+            new RapidMove(1.0, 1.0),
+            new LinearMove(2.0, 1.0) { Layer = LayerType.Leadin },
+            new LinearMove(3.0, 1.0) { Layer = LayerType.Cut }
+        };
+        var ctx = SimpleContext(codes);
+        ctx.IsEtch = true;
+        ctx.LibraryFile = "EtchN2.lib";
+        var output = WriteFeature(config, ctx);
+
+        // Should use #148 for all moves, not #126 for lead-in
+        Assert.DoesNotContain("F#126", output);
+        Assert.Contains("F#148", output);
     }
 
     [Fact]
@@ -378,7 +425,7 @@ public class CincinnatiFeatureWriterTests
         ctx.IsLastFeatureOnSheet = false;
         var output = WriteFeature(config, ctx);
 
-        Assert.Contains("M47 P2000(Safety Headraise)", output);
+        Assert.Contains("M47 P2000 (Safety Headraise)", output);
     }
 
     [Fact]
@@ -404,7 +451,7 @@ public class CincinnatiFeatureWriterTests
         var lines = output.Split(Environment.NewLine, StringSplitOptions.RemoveEmptyEntries);
 
         // Find indices of key lines
-        var rapidIdx = Array.FindIndex(lines, l => l.Contains("G0X"));
+        var rapidIdx = Array.FindIndex(lines, l => l.Contains("G0 X"));
         var partIdx = Array.FindIndex(lines, l => l.Contains("PART:"));
         var g89Idx = Array.FindIndex(lines, l => l.Contains("G89"));
         var g84Idx = Array.FindIndex(lines, l => l.Contains("G84"));

OpenNest.Tests/Cincinnati/CincinnatiPostProcessorTests.cs

@@ -17,7 +17,6 @@ public class CincinnatiPostProcessorTests
         var config = new CincinnatiPostConfig
         {
             ConfigurationName = "CL940",
-            DefaultLibraryFile = "MS135N2PANEL.lib",
             PostedAccuracy = 4
         };
         var post = new CincinnatiPostProcessor(config);
@@ -72,7 +71,7 @@ public class CincinnatiPostProcessorTests
         var output = Encoding.UTF8.GetString(ms.ToArray());
 
         // Should only have one sheet subprogram call in main
-        Assert.Contains("N1M98 P101 (SHEET 1)", output);
+        Assert.Contains("N1 M98 P101 (SHEET 1)", output);
         Assert.DoesNotContain("SHEET 2", output);
     }
 
@@ -104,10 +103,19 @@ public class CincinnatiPostProcessorTests
         var config = new CincinnatiPostConfig
         {
             ConfigurationName = "CL940_CORONA",
-            DefaultLibraryFile = "MS135N2PANEL.lib",
+            DefaultAssistGas = "N2",
+            DefaultEtchGas = "N2",
             PostedUnits = Units.Inches,
             KerfCompensation = KerfMode.ControllerSide,
-            UseAntiDive = true
+            UseAntiDive = true,
+            MaterialLibraries = new()
+            {
+                new MaterialLibraryEntry { Material = "Mild Steel", Thickness = 0.135, Gas = "N2", Library = "MS135N2PANEL.lib" }
+            },
+            EtchLibraries = new()
+            {
+                new EtchLibraryEntry { Gas = "N2", Library = "EtchN2.lib" }
+            }
         };
 
         var opts = new JsonSerializerOptions
@@ -119,10 +127,15 @@ public class CincinnatiPostProcessorTests
         var deserialized = JsonSerializer.Deserialize<CincinnatiPostConfig>(json, opts);
 
         Assert.Equal("CL940_CORONA", deserialized.ConfigurationName);
-        Assert.Equal("MS135N2PANEL.lib", deserialized.DefaultLibraryFile);
+        Assert.Equal("N2", deserialized.DefaultAssistGas);
+        Assert.Equal("N2", deserialized.DefaultEtchGas);
         Assert.Equal(Units.Inches, deserialized.PostedUnits);
         Assert.Equal(KerfMode.ControllerSide, deserialized.KerfCompensation);
         Assert.True(deserialized.UseAntiDive);
+        Assert.Single(deserialized.MaterialLibraries);
+        Assert.Equal("MS135N2PANEL.lib", deserialized.MaterialLibraries[0].Library);
+        Assert.Single(deserialized.EtchLibraries);
+        Assert.Equal("EtchN2.lib", deserialized.EtchLibraries[0].Library);
 
         // Enums serialize as strings
         Assert.Contains("\"Inches\"", json);
@@ -157,21 +170,21 @@ public class CincinnatiPostProcessorTests
         var output = Encoding.UTF8.GetString(ms.ToArray());
 
         // Sheet should contain M98 call to part sub-program
-        Assert.Contains("M98P200", output);
+        Assert.Contains("M98 P200", output);
 
         // Should have G92 for local coordinate positioning
-        Assert.Contains("G92X0Y0", output);
+        Assert.Contains("G92 X0 Y0", output);
 
         // Part sub-program definition
         Assert.Contains(":200", output);
         Assert.Contains("G84", output);
 
-        // Sub-program ends with G0X0Y0 and M99
+        // Sub-program ends with G0 X0 Y0 and M99
-        Assert.Contains("G0X0Y0", output);
+        Assert.Contains("G0 X0 Y0", output);
-        Assert.Contains("M99(END OF Square)", output);
+        Assert.Contains("M99 (END OF Square)", output);
 
         // G92 restore after M98 call
-        Assert.Contains("G92X", output);
+        Assert.Contains("G92 X", output);
     }
 
     [Fact]
@@ -198,7 +211,7 @@ public class CincinnatiPostProcessorTests
         var output = Encoding.UTF8.GetString(ms.ToArray());
 
         // Both parts should call the same sub-program
-        var m98Count = System.Text.RegularExpressions.Regex.Matches(output, "M98P200").Count;
+        var m98Count = System.Text.RegularExpressions.Regex.Matches(output, @"M98 P200\b").Count;
         Assert.Equal(2, m98Count);
 
         // Only one sub-program definition
@@ -238,8 +251,8 @@ public class CincinnatiPostProcessorTests
         // Should have two different sub-programs
         Assert.Contains(":200", output);
         Assert.Contains(":201", output);
-        Assert.Contains("M98P200", output);
+        Assert.Contains("M98 P200", output);
-        Assert.Contains("M98P201", output);
+        Assert.Contains("M98 P201", output);
     }
 
     [Fact]
@@ -268,7 +281,7 @@ public class CincinnatiPostProcessorTests
         var output = Encoding.UTF8.GetString(ms.ToArray());
 
         // Regular part uses sub-program
-        Assert.Contains("M98P200", output);
+        Assert.Contains("M98 P200", output);
         Assert.Contains(":200", output);
 
         // Cutoff should NOT have its own sub-program

OpenNest.Tests/Cincinnati/CincinnatiPreambleWriterTests.cs

@@ -13,14 +13,13 @@ public class CincinnatiPreambleWriterTests
         var config = new CincinnatiPostConfig
         {
             ConfigurationName = "CL940",
-            PostedUnits = Units.Inches,
+            PostedUnits = Units.Inches
-            DefaultLibraryFile = "MS135N2PANEL.lib"
         };
         var sb = new StringBuilder();
         using var sw = new StringWriter(sb);
         var writer = new CincinnatiPreambleWriter(config);
 
-        writer.WriteMainProgram(sw, "TestNest", "Mild Steel, 10GA", 2);
+        writer.WriteMainProgram(sw, "TestNest", "Mild Steel, 10GA", 2, "MS135N2PANEL.lib");
 
         var output = sb.ToString();
         Assert.Contains("( NEST TestNest )", output);
@@ -30,8 +29,8 @@ public class CincinnatiPreambleWriterTests
         Assert.Contains("G89 P MS135N2PANEL.lib", output);
         Assert.Contains("M98 P100 (Variable Declaration)", output);
         Assert.Contains("GOTO1 (GOTO SHEET NUMBER)", output);
-        Assert.Contains("N1M98 P101 (SHEET 1)", output);
+        Assert.Contains("N1 M98 P101 (SHEET 1)", output);
-        Assert.Contains("N2M98 P102 (SHEET 2)", output);
+        Assert.Contains("N2 M98 P102 (SHEET 2)", output);
         Assert.Contains("M30 (END OF MAIN)", output);
     }
 
@@ -43,7 +42,7 @@ public class CincinnatiPreambleWriterTests
         using var sw = new StringWriter(sb);
         var writer = new CincinnatiPreambleWriter(config);
 
-        writer.WriteMainProgram(sw, "Test", "", 1);
+        writer.WriteMainProgram(sw, "Test", "", 1, "");
 
         Assert.Contains("G21", sb.ToString());
     }
@@ -56,7 +55,7 @@ public class CincinnatiPreambleWriterTests
         using var sw = new StringWriter(sb);
         var writer = new CincinnatiPreambleWriter(config);
 
-        writer.WriteMainProgram(sw, "Test", "", 1);
+        writer.WriteMainProgram(sw, "Test", "", 1, "");
 
         Assert.Contains("G61", sb.ToString());
     }
@@ -69,7 +68,7 @@ public class CincinnatiPreambleWriterTests
         using var sw = new StringWriter(sb);
         var writer = new CincinnatiPreambleWriter(config);
 
-        writer.WriteMainProgram(sw, "Test", "", 1);
+        writer.WriteMainProgram(sw, "Test", "", 1, "");
 
         Assert.DoesNotContain("G61", sb.ToString());
     }

OpenNest.Tests/Cincinnati/CincinnatiSheetWriterTests.cs

@@ -1,3 +1,4 @@
+using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Text;
@@ -14,7 +15,6 @@ public class CincinnatiSheetWriterTests
     {
         var config = new CincinnatiPostConfig
         {
-            DefaultLibraryFile = "MS135N2PANEL.lib",
             PostedAccuracy = 4
         };
         var plate = new Plate(48.0, 96.0);
@@ -24,14 +24,15 @@ public class CincinnatiSheetWriterTests
         using var sw = new StringWriter(sb);
         var sheetWriter = new CincinnatiSheetWriter(config, new ProgramVariableManager());
 
-        sheetWriter.Write(sw, plate, "TestNest", 1, 101);
+        sheetWriter.Write(sw, plate, "TestNest", 1, 101, "MS135N2PANEL.lib", "EtchN2.lib");
 
         var output = sb.ToString();
         Assert.Contains(":101", output);
         Assert.Contains("( Sheet 1 )", output);
         Assert.Contains("#110=", output);
         Assert.Contains("#111=", output);
-        Assert.Contains("G92X#5021Y#5022", output);
+        Assert.Contains("G92 X#5021 Y#5022", output);
+        Assert.Contains("G89 P MS135N2PANEL.lib", output);
         Assert.Contains("M99", output);
     }
 
@@ -50,11 +51,11 @@ public class CincinnatiSheetWriterTests
         using var sw = new StringWriter(sb);
         var sheetWriter = new CincinnatiSheetWriter(config, new ProgramVariableManager());
 
-        sheetWriter.Write(sw, plate, "TestNest", 1, 101);
+        sheetWriter.Write(sw, plate, "TestNest", 1, 101, "", "");
 
         var output = sb.ToString();
         Assert.Contains("M42", output);
-        Assert.Contains("G0X0Y0", output);
+        Assert.Contains("G0 X0 Y0", output);
         Assert.Contains("M50", output);
     }
 
@@ -68,7 +69,7 @@ public class CincinnatiSheetWriterTests
         using var sw = new StringWriter(sb);
         var sheetWriter = new CincinnatiSheetWriter(config, new ProgramVariableManager());
 
-        sheetWriter.Write(sw, plate, "TestNest", 1, 101);
+        sheetWriter.Write(sw, plate, "TestNest", 1, 101, "", "");
 
         Assert.Equal("", sb.ToString());
     }
@@ -96,7 +97,7 @@ public class CincinnatiSheetWriterTests
         using var sw = new StringWriter(sb);
         var sheetWriter = new CincinnatiSheetWriter(config, new ProgramVariableManager());
 
-        sheetWriter.Write(sw, plate, "TestNest", 1, 101);
+        sheetWriter.Write(sw, plate, "TestNest", 1, 101, "", "");
 
         var output = sb.ToString();
         // Should have two G84 pierce commands (one per contour)
@@ -104,6 +105,80 @@ public class CincinnatiSheetWriterTests
         Assert.Equal(2, g84Count);
     }
 
+    [Fact]
+    public void WriteSheet_EtchFeaturesOrderedBeforeCut()
+    {
+        var config = new CincinnatiPostConfig { PostedAccuracy = 4 };
+        var pgm = new Program();
+        // Cut contour first in program
+        pgm.Codes.Add(new RapidMove(0, 0));
+        pgm.Codes.Add(new LinearMove(5, 0) { Layer = LayerType.Cut });
+        pgm.Codes.Add(new LinearMove(5, 5) { Layer = LayerType.Cut });
+        // Etch contour second in program
+        pgm.Codes.Add(new RapidMove(1, 1));
+        pgm.Codes.Add(new LinearMove(2, 1) { Layer = LayerType.Scribe });
+        pgm.Codes.Add(new LinearMove(2, 2) { Layer = LayerType.Scribe });
+
+        var plate = new Plate(48.0, 96.0);
+        plate.Parts.Add(new Part(new Drawing("MixedPart", pgm)));
+
+        var sb = new StringBuilder();
+        using var sw = new StringWriter(sb);
+        var sheetWriter = new CincinnatiSheetWriter(config, new ProgramVariableManager());
+
+        sheetWriter.Write(sw, plate, "TestNest", 1, 101, "MS250O2.lib", "EtchN2.lib");
+
+        var output = sb.ToString();
+        // Etch (G85) should appear before cut (G84)
+        var g85Idx = output.IndexOf("G85");
+        var g84Idx = output.IndexOf("G84");
+        Assert.True(g85Idx >= 0, "G85 should be present for etch");
+        Assert.True(g84Idx >= 0, "G84 should be present for cut");
+        Assert.True(g85Idx < g84Idx, "G85 (etch) should come before G84 (cut)");
+
+        // Etch uses etch library
+        Assert.Contains("G89 P EtchN2.lib", output);
+        // Cut uses cut library
+        Assert.Contains("G89 P MS250O2.lib", output);
+    }
+
+    [Fact]
+    public void IsFeatureEtch_ReturnsTrueForScribeLayer()
+    {
+        var codes = new List<ICode>
+        {
+            new RapidMove(0, 0),
+            new LinearMove(1, 0) { Layer = LayerType.Scribe },
+            new LinearMove(1, 1) { Layer = LayerType.Scribe }
+        };
+
+        Assert.True(CincinnatiSheetWriter.IsFeatureEtch(codes));
+    }
+
+    [Fact]
+    public void IsFeatureEtch_ReturnsFalseForCutLayer()
+    {
+        var codes = new List<ICode>
+        {
+            new RapidMove(0, 0),
+            new LinearMove(1, 0) { Layer = LayerType.Cut },
+            new LinearMove(1, 1) { Layer = LayerType.Cut }
+        };
+
+        Assert.False(CincinnatiSheetWriter.IsFeatureEtch(codes));
+    }
+
+    [Fact]
+    public void IsFeatureEtch_ReturnsFalseForRapidsOnly()
+    {
+        var codes = new List<ICode>
+        {
+            new RapidMove(0, 0)
+        };
+
+        Assert.False(CincinnatiSheetWriter.IsFeatureEtch(codes));
+    }
+
     private static Program CreateSimpleProgram()
     {
         var pgm = new Program();