diff --git a/frontend/src/png/overlay.test.ts b/frontend/src/png/overlay.test.ts
index 77fa22e..9e071be 100644
--- a/frontend/src/png/overlay.test.ts
+++ b/frontend/src/png/overlay.test.ts
@@ -5,9 +5,11 @@ import {
   pickBottomTowardTop,
   axisRightUnit,
   buildOverlayPlan,
+  inventorySourceMap,
   type OverlayPlan,
 } from './overlay.ts';
 import { orientedRect, minAreaRect } from '../geometry/rect.ts';
+import { axisEndpoints } from '../measure/measure.ts';
 
 // --- Station math (#63) ---
 
@@ -292,3 +294,186 @@ test('buildOverlayPlan: font one step smaller than prior 28 / scale*1.2 (#67)',
   // Concrete contract: max(22, round(scale*1.0))
   assert.equal(plan.fontPx, Math.max(22, Math.round(scale * 1.0)));
 });
+
+
+// --- Length dim must not overshoot wood footprint (#69) ---
+
+/** Tilted-axis slab: irregular mask + approved bbox long side ~10° from vertical. */
+function tiltedSlabFixture() {
+  const W = 300, H = 600;
+  const bitset = new Uint8Array(W * H);
+  for (let y = 50; y <= 550; y++) {
+    const t = (y - 50) / 500;
+    const x0 = Math.round(80 + t * 20);
+    const x1 = Math.round(180 + t * 40);
+    for (let x = x0; x <= x1; x++) bitset[y * W + x] = 1;
+  }
+  const ang = (10 * Math.PI) / 180;
+  const ux0 = Math.sin(ang);
+  const uy0 = Math.cos(ang);
+  const rx0 = -uy0;
+  const ry0 = ux0;
+  const cx = 140, cy = 300, halfL = 280, halfW = 90;
+  const corners: [number, number][] = [
+    [cx + ux0 * halfL + rx0 * halfW, cy + uy0 * halfL + ry0 * halfW],
+    [cx + ux0 * halfL - rx0 * halfW, cy + uy0 * halfL - ry0 * halfW],
+    [cx - ux0 * halfL - rx0 * halfW, cy - uy0 * halfL - ry0 * halfW],
+    [cx - ux0 * halfL + rx0 * halfW, cy - uy0 * halfL + ry0 * halfW],
+  ];
+  const bbox = { corners, longSidePx: halfL * 2, angleDeg: 80 };
+  return { W, H, bitset, bbox };
+}
+
+function maskWoodAabb(bitset: Uint8Array, W: number, H: number) {
+  let minX = W, maxX = 0, minY = H, maxY = 0;
+  for (let y = 0; y < H; y++) {
+    for (let x = 0; x < W; x++) {
+      if (!bitset[y * W + x]) continue;
+      if (x < minX) minX = x;
+      if (x > maxX) maxX = x;
+      if (y < minY) minY = y;
+      if (y > maxY) maxY = y;
+    }
+  }
+  return { minX, maxX, minY, maxY };
+}
+
+test('buildOverlayPlan: length axial span = tip span; inventory y stays within wood AABB (#69)', () => {
+  const { W, H, bitset, bbox } = tiltedSlabFixture();
+  const scale = 10;
+  const wood = maskWoodAabb(bitset, W, H);
+  const slabBounds = {
+    x: wood.minX - 8,
+    y: wood.minY - 8,
+    w: wood.maxX - wood.minX + 16,
+    h: wood.maxY - wood.minY + 16,
+  };
+  const inv = inventorySourceMap(slabBounds, { widthPx: W, heightPx: H }, 900, 1200);
+  const plan = buildOverlayPlan({
+    bitset,
+    widthPx: W,
+    heightPx: H,
+    bbox,
+    scale,
+    lengthIn: 50,
+    lengthLabel: '50"',
+    mapToInventory: inv.mapToInventory,
+  });
+
+  // Wood AABB in inventory space
+  let mMinY = Infinity, mMaxY = -Infinity;
+  let mMinX = Infinity, mMaxX = -Infinity;
+  for (let y = 0; y < H; y++) {
+    for (let x = 0; x < W; x++) {
+      if (!bitset[y * W + x]) continue;
+      const [mx, my] = inv.mapToInventory(x, y);
+      if (my < mMinY) mMinY = my;
+      if (my > mMaxY) mMaxY = my;
+      if (mx < mMinX) mMinX = mx;
+      if (mx > mMaxX) mMaxX = mx;
+    }
+  }
+  const lenMinY = Math.min(plan.length.a[1], plan.length.b[1]);
+  const lenMaxY = Math.max(plan.length.a[1], plan.length.b[1]);
+  // Current bug: (rx,ry)*outward pushes length ends past wood tip y when axis is tilted
+  assert.ok(
+    lenMinY >= mMinY - 1.5,
+    `length top y=${lenMinY.toFixed(1)} must not extend past wood AABB minY=${mMinY.toFixed(1)}`,
+  );
+  assert.ok(
+    lenMaxY <= mMaxY + 1.5,
+    `length bottom y=${lenMaxY.toFixed(1)} must not extend past wood AABB maxY=${mMaxY.toFixed(1)}`,
+  );
+
+  // Measured axial span equals mask tip-to-tip (dim line parallel beside wood)
+  const { start: aa, end: bb } = axisEndpoints(bbox);
+  const ex = bb[0] - aa[0], ey = bb[1] - aa[1], elen = Math.hypot(ex, ey) || 1;
+  const ux = ex / elen, uy = ey / elen;
+  const cx = bbox.corners.reduce((s, c) => s + c[0], 0) / 4;
+  const cy = bbox.corners.reduce((s, c) => s + c[1], 0) / 4;
+  const cProj = cx * ux + cy * uy;
+  let tipMin = Infinity, tipMax = -Infinity;
+  for (let y = 0; y < H; y++) {
+    for (let x = 0; x < W; x++) {
+      if (!bitset[y * W + x]) continue;
+      const p = x * ux + y * uy;
+      if (p < tipMin) tipMin = p;
+      if (p > tipMax) tipMax = p;
+    }
+  }
+  const tipStart: [number, number] = [cx + ux * (tipMin - cProj), cy + uy * (tipMin - cProj)];
+  const tipEnd: [number, number] = [cx + ux * (tipMax - cProj), cy + uy * (tipMax - cProj)];
+  const oriented = pickBottomTowardTop(tipStart, tipEnd);
+  const mapBottom = inv.mapToInventory(oriented.bottom[0], oriented.bottom[1]);
+  const mapTop = inv.mapToInventory(oriented.top[0], oriented.top[1]);
+  const proj = (p: [number, number], o: [number, number]) =>
+    (p[0] - o[0]) * oriented.ux + (p[1] - o[1]) * oriented.uy;
+  const tipSpan = Math.abs(proj(mapTop, mapBottom));
+  const lenSpan = Math.abs(proj(plan.length.b, plan.length.a));
+  assert.ok(
+    Math.abs(lenSpan - tipSpan) <= 2,
+    `length axial span ${lenSpan.toFixed(1)} must equal tip span ${tipSpan.toFixed(1)}`,
+  );
+
+  // Length stays axis-right of wood (clearance to the right in inventory x for this fixture)
+  const lenMidX = (plan.length.a[0] + plan.length.b[0]) / 2;
+  assert.ok(lenMidX > mMaxX + 4, `length dim must sit outside wood on axis-right (x=${lenMidX} vs maxX=${mMaxX})`);
+});
+
+test('buildOverlayPlan: width labels fully left of wood AABB after inventory map (#69)', () => {
+  const { W, H, bitset, bbox } = tiltedSlabFixture();
+  const scale = 10;
+  const wood = maskWoodAabb(bitset, W, H);
+  const slabBounds = {
+    x: wood.minX - 8,
+    y: wood.minY - 8,
+    w: wood.maxX - wood.minX + 16,
+    h: wood.maxY - wood.minY + 16,
+  };
+  const inv = inventorySourceMap(slabBounds, { widthPx: W, heightPx: H }, 900, 1200);
+  const plan = buildOverlayPlan({
+    bitset,
+    widthPx: W,
+    heightPx: H,
+    bbox,
+    scale,
+    lengthIn: 50,
+    lengthLabel: '50"',
+    mapToInventory: inv.mapToInventory,
+  });
+  assert.ok(plan.widths.length > 0, 'expected width stations');
+
+  let mMinX = Infinity, mMaxX = -Infinity, mMinY = Infinity, mMaxY = -Infinity;
+  for (let y = 0; y < H; y++) {
+    for (let x = 0; x < W; x++) {
+      if (!bitset[y * W + x]) continue;
+      const [mx, my] = inv.mapToInventory(x, y);
+      if (mx < mMinX) mMinX = mx;
+      if (mx > mMaxX) mMaxX = mx;
+      if (my < mMinY) mMinY = my;
+      if (my > mMaxY) mMaxY = my;
+    }
+  }
+
+  for (const w of plan.widths) {
+    // Label anchor fully off the wood footprint (axis-left), with margin for glyph half-width
+    const margin = plan.fontPx * 0.55; // textAlign will grow away from wood; still keep anchor clear
+    const onWood =
+      w.labelAt[0] >= mMinX - 1 &&
+      w.labelAt[0] <= mMaxX + 1 &&
+      w.labelAt[1] >= mMinY - 1 &&
+      w.labelAt[1] <= mMaxY + 1;
+    assert.ok(
+      !onWood,
+      `width labelAt (${w.labelAt[0].toFixed(0)},${w.labelAt[1].toFixed(0)}) must be outside wood AABB`,
+    );
+    // Axis-left = past the left tip (smaller across); for this nearly-vertical slab, left of wood in x
+    assert.ok(
+      w.labelAt[0] < mMinX - 2,
+      `width label ${w.label} x=${w.labelAt[0].toFixed(0)} must be left of wood minX=${mMinX.toFixed(0)} (margin~${margin.toFixed(0)})`,
+    );
+    // Width arrows still touch wood edges (left/right tips inside/on AABB)
+    assert.ok(w.left[0] >= mMinX - 3 && w.left[0] <= mMaxX + 3);
+    assert.ok(w.right[0] >= mMinX - 3 && w.right[0] <= mMaxX + 3);
+  }
+});