diff --git a/demo/client/html/text-demo.html.hbs b/demo/client/html/text-demo.html.hbs
index 073d1f39..eabb16c0 100644
--- a/demo/client/html/text-demo.html.hbs
+++ b/demo/client/html/text-demo.html.hbs
@@ -80,6 +80,12 @@
                                     {{>partials/switch.html id="pf-stem-darkening"
                                       title="Stem Darkening"}}
                                 </div>
+                                <div class="form-group">
+                                    <label for="pf-embolden">Faux Bold</label>
+                                    <input class="form-control" id="pf-embolden" type="range"
+                                     min="-0.015" max="0.015" step="0.0005" value="0.0"
+                                     autocomplete="off">
+                                </div>
                             </form>
                         </div>
                         <div class="pf-arrow-box"></div>
diff --git a/demo/client/src/atlas.ts b/demo/client/src/atlas.ts
index 60caf16f..94e23008 100644
--- a/demo/client/src/atlas.ts
+++ b/demo/client/src/atlas.ts
@@ -35,7 +35,7 @@ export class Atlas {
                  pixelsPerUnit: number,
                  rotationAngle: number,
                  hint: Hint,
-                 stemDarkeningAmount: glmatrix.vec2):
+                 emboldenAmount: glmatrix.vec2):
                  void {
         let nextOrigin = glmatrix.vec2.fromValues(1.0, 1.0);
         let shelfBottom = 2.0;
@@ -46,7 +46,7 @@ export class Atlas {
             if (metrics == null)
                 continue;
 
-            const unitMetrics = new UnitMetrics(metrics, rotationAngle, stemDarkeningAmount);
+            const unitMetrics = new UnitMetrics(metrics, rotationAngle, emboldenAmount);
             glyph.setPixelLowerLeft(nextOrigin, unitMetrics, pixelsPerUnit);
 
             let pixelOrigin = glyph.calculateSubpixelOrigin(pixelsPerUnit);
diff --git a/demo/client/src/text-demo.ts b/demo/client/src/text-demo.ts
index f9b04d78..f3317323 100644
--- a/demo/client/src/text-demo.ts
+++ b/demo/client/src/text-demo.ts
@@ -122,6 +122,7 @@ class TextDemoController extends DemoAppController<TextDemoView> {
     atlasGlyphs: AtlasGlyph[];
 
     private hintingSelect: HTMLSelectElement;
+    private emboldenInput: HTMLInputElement;
 
     private editTextModal: HTMLElement;
     private editTextArea: HTMLTextAreaElement;
@@ -132,6 +133,7 @@ class TextDemoController extends DemoAppController<TextDemoView> {
 
     private _fontSize: number;
     private _rotationAngle: number;
+    private _emboldenAmount: number;
 
     private text: string;
 
@@ -146,11 +148,16 @@ class TextDemoController extends DemoAppController<TextDemoView> {
 
         this._fontSize = INITIAL_FONT_SIZE;
         this._rotationAngle = 0.0;
+        this._emboldenAmount = 0.0;
 
         this.hintingSelect = unwrapNull(document.getElementById('pf-hinting-select')) as
             HTMLSelectElement;
         this.hintingSelect.addEventListener('change', () => this.hintingChanged(), false);
 
+        this.emboldenInput = unwrapNull(document.getElementById('pf-embolden')) as
+            HTMLInputElement;
+        this.emboldenInput.addEventListener('input', () => this.emboldenAmountChanged(), false);
+
         this.editTextModal = unwrapNull(document.getElementById('pf-edit-text-modal'));
         this.editTextArea = unwrapNull(document.getElementById('pf-edit-text-area')) as
             HTMLTextAreaElement;
@@ -167,6 +174,10 @@ class TextDemoController extends DemoAppController<TextDemoView> {
         window.jQuery(this.editTextModal).modal();
     }
 
+    get emboldenAmount(): number {
+        return this._emboldenAmount;
+    }
+
     protected createView(gammaLUT: HTMLImageElement,
                          commonShaderSource: string,
                          shaderSources: ShaderMap<ShaderProgramSource>):
@@ -183,6 +194,11 @@ class TextDemoController extends DemoAppController<TextDemoView> {
         this.view.then(view => view.renderer.updateHinting());
     }
 
+    private emboldenAmountChanged(): void {
+        this._emboldenAmount = parseFloat(this.emboldenInput.value);
+        this.view.then(view => view.renderer.updateEmboldenAmount());
+    }
+
     private updateText(): void {
         this.text = this.editTextArea.value;
         window.jQuery(this.editTextModal).modal('hide');
@@ -246,8 +262,12 @@ class TextDemoController extends DemoAppController<TextDemoView> {
         this.view.then(view => view.renderer.relayoutText());
     }
 
+    get unitsPerEm(): number {
+        return this.font.opentypeFont.unitsPerEm;
+    }
+
     get pixelsPerUnit(): number {
-        return this._fontSize / this.font.opentypeFont.unitsPerEm;
+        return this._fontSize / this.unitsPerEm;
     }
 
     get useHinting(): boolean {
@@ -391,6 +411,12 @@ class TextDemoRenderer extends TextRenderer {
         return this.renderContext.appController.rotationAngle;
     }
 
+    protected get extraEmboldenAmount(): glmatrix.vec2 {
+        const appController = this.renderContext.appController;
+        const emboldenLength = appController.emboldenAmount * appController.unitsPerEm;
+        return glmatrix.vec2.clone([emboldenLength, emboldenLength]);
+    }
+
     prepareToAttachText(): void {
         if (this.atlasFramebuffer == null)
             this.createAtlasFramebuffer();
@@ -428,6 +454,13 @@ class TextDemoRenderer extends TextRenderer {
         this.renderContext.setDirty();
     }
 
+    updateEmboldenAmount(): void {
+        // Likewise, need to relayout the text.
+        this.layoutText();
+        this.buildGlyphs();
+        this.renderContext.setDirty();
+    }
+
     viewPanned(): void {
         this.buildGlyphs();
         this.renderContext.setDirty();
@@ -513,7 +546,7 @@ class TextDemoRenderer extends TextRenderer {
             run.recalculatePixelRects(pixelsPerUnit,
                                       rotationAngle,
                                       hint,
-                                      this.stemDarkeningAmount,
+                                      this.emboldenAmount,
                                       SUBPIXEL_GRANULARITY,
                                       textBounds);
 
@@ -638,7 +671,7 @@ class TextDemoRenderer extends TextRenderer {
 
                 const atlasGlyphUnitMetrics = new UnitMetrics(atlasGlyphMetrics,
                                                               rotationAngle,
-                                                              this.stemDarkeningAmount);
+                                                              this.emboldenAmount);
 
                 const atlasGlyphPixelOrigin =
                     atlasGlyph.calculateSubpixelOrigin(pixelsPerUnit);
diff --git a/demo/client/src/text-renderer.ts b/demo/client/src/text-renderer.ts
index cbe9c57f..fb432da9 100644
--- a/demo/client/src/text-renderer.ts
+++ b/demo/client/src/text-renderer.ts
@@ -81,7 +81,9 @@ export abstract class TextRenderer extends Renderer {
     }
 
     get emboldenAmount(): glmatrix.vec2 {
-        return this.stemDarkeningAmount;
+        const emboldenAmount = glmatrix.vec2.create();
+        glmatrix.vec2.add(emboldenAmount, this.extraEmboldenAmount, this.stemDarkeningAmount);
+        return emboldenAmount;
     }
 
     get bgColor(): glmatrix.vec4 {
@@ -127,6 +129,10 @@ export abstract class TextRenderer extends Renderer {
         return this.meshes == null ? 0 : this.meshes.length;
     }
 
+    protected get extraEmboldenAmount(): glmatrix.vec2 {
+        return glmatrix.vec2.create();
+    }
+
     private stemDarkening: StemDarkeningMode;
     private subpixelAA: SubpixelAAType;
 
@@ -162,9 +168,7 @@ export abstract class TextRenderer extends Renderer {
             const atlasGlyphMetrics = font.metricsForGlyph(glyph.glyphKey.id);
             if (atlasGlyphMetrics == null)
                 continue;
-            const atlasUnitMetrics = new UnitMetrics(atlasGlyphMetrics,
-                                                     0.0,
-                                                     this.stemDarkeningAmount);
+            const atlasUnitMetrics = new UnitMetrics(atlasGlyphMetrics, 0.0, this.emboldenAmount);
 
             const pathID = glyph.pathID;
             boundingRects[pathID * 4 + 0] = atlasUnitMetrics.left;
@@ -201,7 +205,8 @@ export abstract class TextRenderer extends Renderer {
     protected clearForDirectRendering(): void {}
 
     protected buildAtlasGlyphs(atlasGlyphs: AtlasGlyph[]): void {
-        const font = this.renderContext.font;
+        const renderContext = this.renderContext;
+        const font = renderContext.font;
         const pixelsPerUnit = this.pixelsPerUnit;
         const rotationAngle = this.rotationAngle;
         const hint = this.createHint();
@@ -211,13 +216,13 @@ export abstract class TextRenderer extends Renderer {
         if (atlasGlyphs.length === 0)
             return;
 
-        this.renderContext.atlasGlyphs = atlasGlyphs;
-        this.renderContext.atlas.layoutGlyphs(atlasGlyphs,
-                                              font,
-                                              pixelsPerUnit,
-                                              rotationAngle,
-                                              hint,
-                                              this.stemDarkeningAmount);
+        renderContext.atlasGlyphs = atlasGlyphs;
+        renderContext.atlas.layoutGlyphs(atlasGlyphs,
+                                         font,
+                                         pixelsPerUnit,
+                                         rotationAngle,
+                                         hint,
+                                         this.emboldenAmount);
 
         this.uploadPathTransforms(1);
         this.uploadPathColors(1);
@@ -250,10 +255,10 @@ export abstract class TextRenderer extends Renderer {
         // the ascenders and x-heights of the glyphs are pixel snapped, while they aren't on macOS.
         // But we should really figure out what macOS does…
         const ascender = this.renderContext.font.opentypeFont.ascender;
-        const stemDarkeningAmount = this.stemDarkeningAmount;
-        const stemDarkeningYScale = (ascender + stemDarkeningAmount[1]) / ascender;
+        const emboldenAmount = this.emboldenAmount;
+        const stemDarkeningYScale = (ascender + emboldenAmount[1]) / ascender;
 
-        const stemDarkeningOffset = glmatrix.vec2.clone(stemDarkeningAmount);
+        const stemDarkeningOffset = glmatrix.vec2.clone(emboldenAmount);
         glmatrix.vec2.scale(stemDarkeningOffset, stemDarkeningOffset, pixelsPerUnit);
         glmatrix.vec2.scale(stemDarkeningOffset, stemDarkeningOffset, SQRT_1_2);
         glmatrix.vec2.mul(stemDarkeningOffset, stemDarkeningOffset, [1, stemDarkeningYScale]);
diff --git a/demo/client/src/text.ts b/demo/client/src/text.ts
index 88564cca..66ff6a30 100644
--- a/demo/client/src/text.ts
+++ b/demo/client/src/text.ts
@@ -167,13 +167,13 @@ export class TextRun {
     recalculatePixelRects(pixelsPerUnit: number,
                           rotationAngle: number,
                           hint: Hint,
-                          stemDarkeningAmount: glmatrix.vec2,
+                          emboldenAmount: glmatrix.vec2,
                           subpixelGranularity: number,
                           textFrameBounds: glmatrix.vec4):
                           void {
         for (let index = 0; index < this.glyphIDs.length; index++) {
             const metrics = unwrapNull(this.font.metricsForGlyph(this.glyphIDs[index]));
-            const unitMetrics = new UnitMetrics(metrics, rotationAngle, stemDarkeningAmount);
+            const unitMetrics = new UnitMetrics(metrics, rotationAngle, emboldenAmount);
             const textGlyphOrigin = this.calculatePixelOriginForGlyphAt(index,
                                                                         pixelsPerUnit,
                                                                         rotationAngle,
@@ -381,11 +381,11 @@ export class UnitMetrics {
     ascent: number;
     descent: number;
 
-    constructor(metrics: Metrics, rotationAngle: number, stemDarkeningAmount: glmatrix.vec2) {
+    constructor(metrics: Metrics, rotationAngle: number, emboldenAmount: glmatrix.vec2) {
         const left = metrics.xMin;
         const bottom = metrics.yMin;
-        const right = metrics.xMax + stemDarkeningAmount[0] * 2;
-        const top = metrics.yMax + stemDarkeningAmount[1] * 2;
+        const right = metrics.xMax + emboldenAmount[0] * 2;
+        const top = metrics.yMax + emboldenAmount[1] * 2;
 
         const transform = glmatrix.mat2.create();
         glmatrix.mat2.fromRotation(transform, -rotationAngle);