diff --git a/src/editor/debugHook.ts b/src/editor/debugHook.ts
index ef6ca890..4e8f73e2 100644
--- a/src/editor/debugHook.ts
+++ b/src/editor/debugHook.ts
@@ -315,6 +315,7 @@ export function installDebugHook(app: Application, state: EditorState, editor: E
       pickerWidth: () => textureEditor.picker.w,
       /** Where an image pixel of the shown sheet sits on screen (frames are dragged in image coordinates). */
       pointAt: (x: number, y: number) => textureEditor.imageToScreen(x, y),
+      rect: () => textureEditor.canvasRect(),
     },
     animation: {
       /** Frames, the one on screen, play state and where the preview picture is drawn. */
diff --git a/src/editor/texture/TextureCanvas.ts b/src/editor/texture/TextureCanvas.ts
index e625345d..92ace0bc 100644
--- a/src/editor/texture/TextureCanvas.ts
+++ b/src/editor/texture/TextureCanvas.ts
@@ -61,8 +61,9 @@ interface NewFrame {
  */
 export class TextureCanvas extends Widget {
   private readonly bg = new Graphics();
+  /** Everything the view can move: panned or zoomed, all of it reaches past the widget. */
+  private readonly content = new Container();
   private readonly checker = new Graphics();
-  private readonly imageLayer = new Container();
   private readonly image = new Sprite();
   private readonly overlay = new Graphics();
   private readonly labels = new Map<string, Text>();
@@ -79,20 +80,10 @@ export class TextureCanvas extends Widget {
 
   constructor(private readonly state: EditorState) {
     super();
-    this.imageLayer.addChild(this.image);
-    this.addChild(
-      this.bg,
-      this.checker,
-      this.imageLayer,
-      this.overlay,
-      this.labelLayer,
-      this.hint,
-      this.clip,
-    );
-    this.imageLayer.mask = this.clip;
-    this.imageLayer.eventMode = 'none';
-    this.overlay.eventMode = 'none';
-    this.labelLayer.eventMode = 'none';
+    this.content.addChild(this.checker, this.image, this.overlay, this.labelLayer);
+    this.addChild(this.bg, this.content, this.hint, this.clip);
+    this.content.mask = this.clip;
+    this.content.eventMode = 'none';
     this.hint.eventMode = 'none';
     this.focusable = true;
 
diff --git a/src/editor/texture/TextureEditor.ts b/src/editor/texture/TextureEditor.ts
index 78ccc68f..a3753448 100644
--- a/src/editor/texture/TextureEditor.ts
+++ b/src/editor/texture/TextureEditor.ts
@@ -23,6 +23,12 @@ export class TextureEditor extends AssetTabEditor<TextureAsset, TextureCanvas> {
     return this.canvas.imageToScreen(x, y);
   }
 
+  /** The drawing area without the header, so a check can ask what lies outside it. */
+  canvasRect(): { x: number; y: number; w: number; h: number } {
+    const p = this.canvas.getGlobalPosition();
+    return { x: p.x, y: p.y, w: this.canvas.w, h: this.canvas.h };
+  }
+
   protected override selectedId(): string {
     return this.state.selectedTextureId ?? '';
   }
diff --git a/tools/e2e/13-frames.mjs b/tools/e2e/13-frames.mjs
index fc3fbdf6..2a6d03d7 100644
--- a/tools/e2e/13-frames.mjs
+++ b/tools/e2e/13-frames.mjs
@@ -34,7 +34,7 @@ function nearestColour(sample) {
 }
 
 export async function frames(t) {
-  const { check, sleep, json, evaluate, shot, clickText, drag, press, undo } = t;
+  const { check, sleep, json, evaluate, shot, clickText, drag, press, undo, wheel } = t;
 
   // 13a. The tab exists and shows the texture the selection points at.
   await press('Escape');
@@ -156,7 +156,50 @@ export async function frames(t) {
   check('and numbers them in reading order', sliced[0]?.startsWith('Frame 1 '), JSON.stringify(sliced[0]));
   await shot('36-sliced-sheet');
 
-  // 13f. A sprite pointed at a frame slicing removed falls back to its colour.
+  // 13f. Zoomed in, the sheet is larger than the tab: nothing of it may be drawn next to the tab.
+  //      The bug this guards against drew the checkerboard's base rectangle, the frame outlines
+  //      and the name plates over the Assets panel, because only the picture itself was masked.
+  await evaluate("__gm.showTab('texture')");
+  await sleep(400);
+  const area = await json('__gm.texture.rect()');
+  // Points on the panel left of the tab and on the tab row above it – both were painted over.
+  const probes = [
+    ...[0.2, 0.4, 0.6, 0.8].map((f) => ({ x: Math.round(area.x - 40), y: Math.round(area.y + f * area.h) })),
+    ...[0.25, 0.5, 0.75].map((f) => ({ x: Math.round(area.x + f * area.w), y: Math.round(area.y - 10) })),
+  ];
+  const readProbes = async () => {
+    const out = [];
+    for (const p of probes) out.push(await json(`__gm.pixelAt(${p.x}, ${p.y})`));
+    return out;
+  };
+  const quiet = await readProbes();
+
+  const centre = { x: Math.round(area.x + area.w / 2), y: Math.round(area.y + area.h / 2) };
+  for (let i = 0; i < 6; i++) await wheel(centre.x, centre.y, -240);
+  await sleep(500);
+  const topLeft = await json('__gm.texture.pointAt(0, 0)');
+  // Without this the probes below would prove nothing: they need a sheet that reaches past the edge.
+  check(
+    'zooming in pushes the sheet past the tab on every side',
+    topLeft.x < area.x && topLeft.y < area.y,
+    JSON.stringify({ topLeft, area }),
+  );
+  await shot('36b-zoomed-sheet');
+
+  const loud = await readProbes();
+  const changed = probes
+    .map((p, i) => ({ ...p, was: quiet[i], now: loud[i] }))
+    .filter((p) => p.was !== p.now);
+  check('a zoomed sheet paints nothing outside the tab', changed.length === 0, JSON.stringify(changed));
+  check(
+    'and no frame name is drawn past the tab either',
+    (await json('__gm.textOverflows()')).length === 0,
+    JSON.stringify(await json('__gm.textOverflows()')),
+  );
+  await clickText('Fit');
+  await sleep(400);
+
+  // 13g. A sprite pointed at a frame slicing removed falls back to its colour.
   await evaluate("__gm.showTab('scene')");
   await sleep(700);
   if (box) {