diff --git a/tests/fixtures/labelPlacementDefects.ts b/tests/fixtures/labelPlacementDefects.ts
new file mode 100644
index 000000000..f3c7fa5f2
--- /dev/null
+++ b/tests/fixtures/labelPlacementDefects.ts
@@ -0,0 +1,108 @@
+import type { NetLabelPlacement } from "lib/solvers/NetLabelPlacementSolver/NetLabelPlacementSolver"
+import type { InputProblem } from "lib/types/InputProblem"
+
+const EPS = 1e-9
+
+type Bounds = { minX: number; maxX: number; minY: number; maxY: number }
+
+const boundsOf = (
+  center: { x: number; y: number },
+  width: number,
+  height: number,
+): Bounds => ({
+  minX: center.x - width / 2,
+  maxX: center.x + width / 2,
+  minY: center.y - height / 2,
+  maxY: center.y + height / 2,
+})
+
+/** Interior overlap: touching edges are not an overlap. */
+const overlaps = (a: Bounds, b: Bounds) =>
+  a.minX < b.maxX - EPS &&
+  a.maxX > b.minX + EPS &&
+  a.minY < b.maxY - EPS &&
+  a.maxY > b.minY + EPS
+
+/**
+ * Fraction of `inner`'s area covered by `outer`.
+ */
+const coverageFraction = (inner: Bounds, outer: Bounds) => {
+  const overlapWidth = Math.max(
+    0,
+    Math.min(inner.maxX, outer.maxX) - Math.max(inner.minX, outer.minX),
+  )
+  const overlapHeight = Math.max(
+    0,
+    Math.min(inner.maxY, outer.maxY) - Math.max(inner.minY, outer.minY),
+  )
+  const area = (inner.maxX - inner.minX) * (inner.maxY - inner.minY)
+
+  return area > 0 ? (overlapWidth * overlapHeight) / area : 0
+}
+
+/**
+ * Mirrors `CHIP_COLLISION_MIN_OVERLAP_FRACTION` in
+ * `NetLabelNetLabelCollisionSolver`: a label counts as "inside" a chip only
+ * once the chip covers at least half of it. Smaller incidental overlaps are
+ * tolerated there deliberately, so counting them would report defects the
+ * solver is intentionally leaving alone.
+ */
+const INSIDE_CHIP_MIN_COVERAGE = 0.5
+
+/**
+ * Net labels substantially covered by a chip body. These render behind the
+ * component and are illegible — see #655.
+ */
+export const getLabelsInsideChips = (
+  labels: NetLabelPlacement[],
+  inputProblem: InputProblem,
+) => {
+  const offenders: Array<{ netId: string; chipId: string }> = []
+
+  for (const label of labels) {
+    const labelBounds = boundsOf(label.center, label.width, label.height)
+
+    for (const chip of inputProblem.chips) {
+      const chipBounds = boundsOf(chip.center, chip.width, chip.height)
+      if (
+        !overlaps(labelBounds, chipBounds) ||
+        coverageFraction(labelBounds, chipBounds) < INSIDE_CHIP_MIN_COVERAGE
+      ) {
+        continue
+      }
+      offenders.push({
+        netId: label.netId ?? label.globalConnNetId,
+        chipId: chip.chipId,
+      })
+      break
+    }
+  }
+
+  return offenders
+}
+
+/** Pairs of net labels whose boxes overlap each other. */
+export const getOverlappingLabelPairs = (labels: NetLabelPlacement[]) => {
+  const pairs: Array<{ a: string; b: string }> = []
+
+  for (let i = 0; i < labels.length; i++) {
+    for (let k = i + 1; k < labels.length; k++) {
+      const a = labels[i]!
+      const b = labels[k]!
+      if (
+        !overlaps(
+          boundsOf(a.center, a.width, a.height),
+          boundsOf(b.center, b.width, b.height),
+        )
+      ) {
+        continue
+      }
+      pairs.push({
+        a: a.netId ?? a.globalConnNetId,
+        b: b.netId ?? b.globalConnNetId,
+      })
+    }
+  }
+
+  return pairs
+}
diff --git a/tests/net-label-placement-defects.test.ts b/tests/net-label-placement-defects.test.ts
new file mode 100644
index 000000000..47d129180
--- /dev/null
+++ b/tests/net-label-placement-defects.test.ts
@@ -0,0 +1,77 @@
+import { expect, test } from "bun:test"
+import fs from "node:fs"
+import path from "node:path"
+import { SchematicTracePipelineSolver } from "lib/solvers/SchematicTracePipelineSolver/SchematicTracePipelineSolver"
+import {
+  getLabelsInsideChips,
+  getOverlappingLabelPairs,
+} from "tests/fixtures/labelPlacementDefects"
+
+/**
+ * Net-label placement defects per board: labels rendered inside a chip body
+ * (illegible — see #655) and labels overlapping each other.
+ *
+ * These are current values, not targets. Several are open bugs. Pinning them
+ * means a placement change that makes a board worse fails a named assertion
+ * instead of disappearing into a regenerated SVG snapshot.
+ *
+ * If a change legitimately improves a board, lower the number in the same PR.
+ */
+const EXPECTED: Record<
+  string,
+  { insideChips: number; overlappingPairs: number }
+> = {
+  "bug-report-20260706T213649Z": { insideChips: 0, overlappingPairs: 0 },
+  "bug-report-20260706T220324Z": { insideChips: 0, overlappingPairs: 1 },
+  "bug-report-20260707T020342Z": { insideChips: 0, overlappingPairs: 0 },
+  "bug-report-20260707T092615Z": { insideChips: 1, overlappingPairs: 1 },
+  "bug-report-20260707T134549Z": { insideChips: 0, overlappingPairs: 1 },
+  "bug-report-20260707T134722Z": { insideChips: 0, overlappingPairs: 0 },
+  "bug-report-20260707T140410Z": { insideChips: 0, overlappingPairs: 1 },
+  "bug-report-20260707T141025Z": { insideChips: 1, overlappingPairs: 0 },
+  "bug-report-20260707T141421Z": { insideChips: 1, overlappingPairs: 1 },
+  "bug-report-20260707T230831Z": { insideChips: 4, overlappingPairs: 0 },
+  "bug-report-20260708T053736Z": { insideChips: 0, overlappingPairs: 0 },
+  "bug-report-20260708T055430Z": { insideChips: 0, overlappingPairs: 0 },
+  "bug-report-20260708T095725Z": { insideChips: 0, overlappingPairs: 0 },
+  "bug-report-20260716T144856Z": { insideChips: 1, overlappingPairs: 0 },
+  "bug-report-20260717T022934Z": { insideChips: 0, overlappingPairs: 0 },
+  "bug-report-20260717T031704Z": { insideChips: 0, overlappingPairs: 0 },
+  "bug-report-20260717T042845Z": { insideChips: 0, overlappingPairs: 0 },
+  "bug-report-20260721T221026Z": { insideChips: 0, overlappingPairs: 2 },
+  "bug-report-20260724T175257Z": { insideChips: 0, overlappingPairs: 0 },
+}
+
+const BUG_REPORTS_DIR = path.join(import.meta.dir, "bug-reports")
+
+const measure = (board: string) => {
+  const inputPath = path.join(BUG_REPORTS_DIR, board, `${board}.json`)
+  const inputProblem = JSON.parse(fs.readFileSync(inputPath, "utf8"))
+
+  const solver = new SchematicTracePipelineSolver(inputProblem as any)
+  solver.solve()
+
+  // The *output* copy — `netLabelPlacements` on the solver is its input.
+  const labels =
+    solver.netLabelNetLabelCollisionSolver?.getOutput().netLabelPlacements ?? []
+
+  return {
+    insideChips: getLabelsInsideChips(labels, solver.inputProblem).length,
+    overlappingPairs: getOverlappingLabelPairs(labels).length,
+  }
+}
+
+test("every pinned board still exists", () => {
+  const onDisk = fs
+    .readdirSync(BUG_REPORTS_DIR)
+    .filter((d) => fs.existsSync(path.join(BUG_REPORTS_DIR, d, `${d}.json`)))
+    .sort()
+
+  expect(onDisk).toEqual(Object.keys(EXPECTED).sort())
+})
+
+for (const [board, expected] of Object.entries(EXPECTED)) {
+  test(`${board} label placement defects`, () => {
+    expect(measure(board)).toEqual(expected)
+  })
+}