diff --git a/font-src/meta/aesthetics.ptl b/font-src/meta/aesthetics.ptl
index 4b9631591..d6b47fb11 100644
--- a/font-src/meta/aesthetics.ptl
+++ b/font-src/meta/aesthetics.ptl
@@ -289,11 +289,18 @@ export : define [copyFontMetrics fm1 fm2] : begin
 	set fm2.post.underlineThickness  fm1.post.underlineThickness
 
 
+class CMarkSet
+	public [new markAnchors baseAnchors] : begin
+		set this.markAnchors markAnchors
+		set this.baseAnchors baseAnchors
+	public [applyToGlyph g] : begin
+		g.copyAnchors this
+
 export : define [compositeBaseAnchors] : begin
-	local h {.}
+	local baseAnchorSink {.}
 	foreach a [items-of arguments] : foreach k [items-of [Object.keys a.baseAnchors]] : begin
-		set h.(k) : new Anchor a.baseAnchors.(k).x a.baseAnchors.(k).y a.baseAnchors.(k).type a.baseAnchors.(k).mbx a.baseAnchors.(k).mby
-	return {.baseAnchors h .isMarkSet true}
+		set baseAnchorSink.(k) : new Anchor a.baseAnchors.(k).x a.baseAnchors.(k).y a.baseAnchors.(k).type a.baseAnchors.(k).mbx a.baseAnchors.(k).mby
+	return : new CMarkSet null baseAnchorSink
 
 export : define [MarksetDiv p sbMul me] : begin
 	define width : p * me.Width
@@ -388,16 +395,24 @@ export : define DesignParameters : object
 	# Square dot
 	squareDotScalar            0.95
 
-export : define [GenDivFrame metrics] : lambda [_div _hPack _sbMul] : begin
-	local div : fallback _div 1
-	local hPack : Math.max 2 [fallback _hPack 0]
-	local sbMul : fallback _sbMul : Math.min 1 : (metrics.Width * div - hPack * [metrics.AdviceStroke hPack div]) / (2 * hPack * metrics.SB)
-	return : object
-		div div
-		width : metrics.Width * div
-		middle : metrics.Middle * div
-		sb : metrics.SB * sbMul
-		leftSB : metrics.SB * sbMul
-		rightSB : metrics.Width * div - metrics.SB * sbMul
-		mvs : metrics.AdviceStroke hPack div
-		markSet : MarksetDiv div sbMul metrics
+export : define [GenDivFrame metrics] : begin
+	class CDivFrame
+		public [new _div _hPack _sbMul] : begin
+			local div : fallback _div 1
+			local hPack : Math.max 2 [fallback _hPack 0]
+			local sbMul : fallback _sbMul : Math.min 1 : (metrics.Width * div - hPack * [metrics.AdviceStroke hPack div]) / (2 * hPack * metrics.SB)
+
+			set this.div       div
+			set this.width   : metrics.Width * div
+			set this.middle  : metrics.Middle * div
+			set this.sb      : metrics.SB * sbMul
+			set this.leftSB  : metrics.SB * sbMul
+			set this.rightSB : metrics.Width * div - metrics.SB * sbMul
+			set this.mvs     : metrics.AdviceStroke hPack div
+			set this.markSet : MarksetDiv div sbMul metrics
+
+		public [applyToGlyph g] : begin
+			g.setWidth this.width
+			return this
+
+	return : lambda [_div _hPack _sbMul] : new CDivFrame _div _hPack _sbMul
diff --git a/font-src/support/glyph/index.js b/font-src/support/glyph/index.js
index 3363ad37c..b4dcae09b 100644
--- a/font-src/support/glyph/index.js
+++ b/font-src/support/glyph/index.js
@@ -65,10 +65,10 @@ exports.Glyph = class Glyph {
 			throw new Error("Unreachable: Attempt to include a Null or Undefined");
 		} else if (component instanceof Function) {
 			return component.call(this, copyAnchors, copyWidth);
+		} else if (component.applyToGlyph instanceof Function) {
+			return component.applyToGlyph(this, copyAnchors, copyWidth);
 		} else if (component instanceof Transform) {
 			return this.applyTransform(component, copyAnchors);
-		} else if (component.isMarkSet) {
-			return this.copyAnchors(component);
 		} else if (component instanceof Glyph) {
 			return this.includeGlyph(component, copyAnchors, copyWidth);
 		} else {
@@ -83,7 +83,8 @@ exports.Glyph = class Glyph {
 		this.combineMarks(g, shift);
 
 		this.includeGlyphImpl(g, shift.x, shift.y);
-		if (copyAnchors || g.isMarkSet) this.copyAnchors(g);
+		if (g.isMarkSet) throw new Error("Invalid component to be introduced.");
+		if (copyAnchors) this.copyAnchors(g);
 		if (copyWidth && g.advanceWidth >= 0) this.advanceWidth = g.advanceWidth;
 		this.dependsOn(g);
 	}