diff --git a/app/bridge.py b/app/bridge.py
index 34b27b5..842c3d1 100644
--- a/app/bridge.py
+++ b/app/bridge.py
@@ -199,6 +199,7 @@ class PrinterWorker:
         self.record: dict | None = None
         self.cc2_data: dict | None = None
         self.print_info: dict | None = None  # CC2 Control /api/printer, only read while a job runs
+        self.noted_questions: dict[int, str] = {}  # slot -> question already reported
 
     @property
     def id(self) -> str:
@@ -267,6 +268,7 @@ class PrinterWorker:
             self._reconcile_cc2(cc2)
             self._process_cc2_log(cc2)
             self._consumption(cc2)
+            self._note_open_questions(cc2)
 
     def _record_id(self, n: int) -> int | None:
         for s in self.record_slots:
@@ -406,6 +408,23 @@ class PrinterWorker:
             elif loaded:
                 self._answer_again(n, m, question)
 
+    def _note_open_questions(self, cc2: dict) -> None:
+        """A tray printed while CC2 Control was still asking which spool it holds: say so once, after the print."""
+        if (cc2.get("job") or {}).get("active"):
+            return
+        for slot in cc2.get("slots") or []:
+            n = slot.get("slot")
+            mm = _num(slot.get("question_mm"))
+            if n not in (0, 1, 2, 3) or not slot.get("question") or mm < 1 or str(n) in self.st["slots"]:
+                continue
+            key = f"{n}|{slot.get('question_since')}"
+            if self.noted_questions.get(n) == key:
+                continue
+            self.noted_questions[n] = key
+            self._log("warn", f"Slot {n + 1}: {mm:.0f} mm (ca. {grams_from_mm(mm, 1.75, 1.24):.1f} g) ohne Spule gedruckt; "
+                              "CC2 Control wartet auf die Zuordnung. Rolle taggen und scannen, dann wird der Verbrauch "
+                              "nachgebucht, oder in CC2 Control „keine Spule“ wählen.")
+
     def _reinserted(self, n: int) -> None:
         """No mapping, CC2 Control asks about filament put in, and the record still names the roll
         that last left this slot: it is that roll again."""
@@ -531,6 +550,11 @@ class PrinterWorker:
                     if settled:
                         self._weighin(cid, b, name, smid, rem, newest)
                     continue
+                if any(e.get("kind") == "runout" for e in fresh):
+                    # CC2 Control sets a roll that ran out to zero; Spoolman follows absolutely, so a count
+                    # that was off (e.g. a mirror left with an old value) does not book too much or too little
+                    if not settled or self._weighin(cid, b, name, smid, rem, newest, describe(fresh)):
+                        continue
                 delta = b["remaining"] - rem
                 if delta < -MIN_BOOKING:
                     self._log("warn", f"{name}: Rest in CC2 Control um {-delta:.2f} g gestiegen; "
@@ -589,24 +613,32 @@ class PrinterWorker:
                      details, log_time)
         return True
 
-    def _weighin(self, cid: str, b: dict, name: str, smid: int, rem: float, log_time: float) -> None:
-        """Weighed in CC2 Control: Spoolman takes the weighed value (and any use since) as it is."""
+    def _weighin(self, cid: str, b: dict, name: str, smid: int, rem: float, log_time: float,
+                 runout: str | None = None) -> bool:
+        """Weighed in CC2 Control, or ran out (`runout` holds the print details): Spoolman takes CC2 Control's
+        value as it is. False when Spoolman has no start weight to set it against."""
         sm = self.bridge.spoolman.spool(smid)
         base = sm.get("initial_weight") or (sm.get("filament") or {}).get("weight")
         if not base:
+            what = "Leerlaufen per Verbrauch gebucht" if runout is not None else "Nachwiegen nicht übernommen"
             self.bridge._once_error(f"{self.id}:weigh:{cid}", f"{self.name}: {name}: Spoolman-Spule {smid} hat kein "
-                                                               "Startgewicht; Nachwiegen nicht übernommen")
-            return
+                                                               f"Startgewicht; {what}")
+            return False
         target = max(0.0, rem)
         used = round(max(0.0, float(base) - target), 3)
-        _, done = self._write(f"weigh:{cid}", f"in Spoolman den Rest von {name} auf {target:.1f} g setzen "
-                                              "(in CC2 Control nachgewogen)",
+        prev = _num(sm.get("remaining_weight"), float(base) - _num(sm.get("used_weight")))
+        why = f"(Rolle leergelaufen){runout}" if runout is not None else "(in CC2 Control nachgewogen)"
+        _, done = self._write(f"weigh:{cid}", f"in Spoolman den Rest von {name} auf {target:.1f} g setzen {why}",
                               lambda: self.bridge.spoolman.update_spool(smid, {"used_weight": used}))
         if done:
             b["remaining"] = rem
             b["log_time"] = max(b.get("log_time") or 0.0, log_time)
+            if runout is not None:
+                b["last"] = {"time": self.bridge.clock(), "grams": round(max(0.0, prev - target), 3),
+                             "details": ("Rolle leergelaufen" + runout).replace("leergelaufen – ", "leergelaufen: ")}
             self.bridge.spool_cache.pop(smid, None)
             self.bridge.state.save()
+        return True
 
     # ---------- CC2 Control's log: use of a tray left without spool after "Take out" ----------
 
@@ -691,6 +723,7 @@ class PrinterWorker:
                 "spoolman": summary(cached[1]) if cached else None,
                 "cc2_spool": cc2_spools.get(sid) if sid else None,
                 "cc2_question": cs.get("question") or "",
+                "cc2_question_mm": _num(cs.get("question_mm")) if cs.get("question") else 0.0,
                 "cc2_matches": bool(m and m.get("cc2") and sid == m["cc2"]),
                 "last_booking": (b or {}).get("last"),
             })
diff --git a/app/templates/status.html b/app/templates/status.html
index 4acfdbb..d7daca4 100644
--- a/app/templates/status.html
+++ b/app/templates/status.html
@@ -120,6 +120,14 @@ function info(s) {
       out.title = 'Ohne Spoolman-Tag';
       out.hint = 'Verbrauch wird nicht gebucht. Rolle taggen und scannen, um sie zu verwalten.';
     }
+    if (s.cc2_question) {
+      const mm = s.cc2_question_mm || 0;
+      out.question = 'CC2 fragt: Spule ' + (QUESTION[s.cc2_question] || s.cc2_question);
+      out.hint = mm >= 1
+        ? `Gedruckt ohne Spule: ${fmtNum(mm)} mm (ca. ${fmtNum(mm * Math.PI * 0.765625 * 1.24 / 1000, 1)} g). CC2 Control hält den Verbrauch, bis die Spule feststeht: Rolle taggen und scannen, dann wird er nachgebucht – oder in CC2 Control „keine Spule“ wählen.`
+        : 'CC2 Control fragt, welche Spule das ist. Rolle taggen und scannen oder in CC2 Control beantworten.';
+      out.warn = mm >= 1;
+    }
   }
   return out;
 }
@@ -195,7 +203,8 @@ function slotCard(p, s) {
         <span style="min-width:0"><span class="nm" style="display:block;font-size:15px">${esc(i.title)}</span>
         <span class="small muted" style="display:block">${esc(i.sub)}</span></span>
       </button>
-      <p class="hint${i.kind === 'takeout' ? ' warn' : ''}" style="margin-top:auto">${esc(i.hint)}</p>`;
+      ${i.question ? `<div><span class="chip warn">${esc(i.question)}</span></div>` : ''}
+      <p class="hint${i.kind === 'takeout' || i.warn ? ' warn' : ''}" style="margin-top:auto">${esc(i.hint)}</p>`;
   }
   return `<article class="card slot"><div class="sh"><b>Slot ${s.slot + 1}</b>${tray}</div>${body}</article>`;
 }
@@ -205,6 +214,7 @@ function slotRow(p, s) {
   const inner = `<span style="font-weight:800;font-size:13px">${s.slot + 1}</span>`;
   let title = i.title, sub = i.sub, rest = '';
   if (i.kind === 'empty') { title = 'Leer'; sub = 'Kein Filament'; }
+  if (i.kind === 'unmanaged' && i.question) sub = i.warn ? `${fmtNum(s.cc2_question_mm)} mm ohne Spule gedruckt` : i.question;
   if (i.kind === 'managed') {
     rest = i.rest == null ? '?' : Math.round(i.rest) + ' g';
     sub = [i.sub, '#' + s.mapping.spool, i.question || i.cc2[0]].filter(Boolean).join(' · ');
@@ -282,7 +292,7 @@ function sheetHtml(p, s) {
       <h2 id="sheet-title" style="overflow-wrap:anywhere">${esc(i.title || 'Leer')}</h2>${i.sub ? `<div class="small muted">${esc(i.sub)}</div>` : ''}</div>
       <button aria-label="Schließen" onclick="closeSheet()" style="min-width:40px;padding:0;border-radius:99px">✕</button>
     </div>
-    ${i.hint ? `<p class="hint${i.kind === 'takeout' ? ' warn' : ''}">${esc(i.hint)}</p>` : ''}
+    ${i.hint ? `<p class="hint${i.kind === 'takeout' || i.warn ? ' warn' : ''}">${esc(i.hint)}</p>` : ''}
     <dl class="kv">${rows.map(([k, v]) => `<dt>${k}</dt><dd>${v}</dd>`).join('')}</dl>
     ${m ? `<div class="row" style="flex-wrap:nowrap"><button style="flex:1;min-height:48px" onclick="slotAction('${p.id}', ${s.slot}, 'reassign')">Erneut senden</button>
       <button class="danger" style="flex:1;min-height:48px" onclick="slotAction('${p.id}', ${s.slot}, 'release')">Aufheben</button></div>` : ''}`;
diff --git a/tests/test_bridge.py b/tests/test_bridge.py
index 3d30cac..3340bef 100644
--- a/tests/test_bridge.py
+++ b/tests/test_bridge.py
@@ -740,8 +740,41 @@ def test_runout_and_backup_roll(env):
     cc2.job = {"active": False}
     cc2.add_log(env["clock"](), "print", "s0002", 1, -12.0, 4000.0, "vase.gcode", "complete")
     poll(env, 10)
-    assert sorted(uses(env)) == [("use", 5, 40.0), ("use", 8, 12.0)]
+    assert uses(env) == [("use", 8, 12.0)]
+    assert ("used", 5, 1000.0) in env["sm"].calls  # ran out: Spoolman's rest is 0, whatever the count said
+    assert env["sm"].db[5]["remaining_weight"] == 0
     assert any("Rolle leergelaufen" in m for m in msgs(env))
+    assert booked(env)["s0001"]["last"]["grams"] == 40.0
+
+
+def test_runout_sets_spoolman_to_zero_even_if_the_mirror_was_off(env):
+    env["sm"].add(5, remaining=300)
+    insert(env, 0, 5)
+    poll(env)
+    cc2 = env["cc2"]
+    cc2.library[0]["remaining"] = 400.0  # e.g. an old mirror reused after the roll printed elsewhere
+    booked(env)["s0001"]["remaining"] = 400.0
+    cc2.job = {"active": True}
+    cc2.consume("s0001", 380.0)
+    poll(env)
+    cc2.slots[0]["printer"] = {"status": 0}
+    cc2.slots[0]["spool"] = ""
+    t = env["clock"]()
+    cc2.add_log(t, "runout", "s0001", 0, -20.0, 0, "big.gcode", "runout")
+    cc2.library[0]["remaining"] = 0.0
+    cc2.job = {"active": False}
+    cc2.add_log(t + 5, "print", "s0001", 0, -380.0, 127000.0, "big.gcode", "runout")
+    poll(env, 15)
+    assert uses(env) == [] and env["sm"].db[5]["remaining_weight"] == 0
+
+
+def test_open_question_after_print_is_reported_once(env):
+    cc2 = env["cc2"]
+    cc2.slots[3].update({"printer": {"status": 1}, "question": "changed", "question_since": 100, "question_mm": 2605.0})
+    poll(env, 3)
+    warn = [m for m in msgs(env) if "ohne Spule gedruckt" in m]
+    assert len(warn) == 1 and "2605 mm" in warn[0] and "7.8 g" in warn[0]
+    assert env["bridge"].snapshot["printers"][0]["slots"][3]["cc2_question_mm"] == 2605.0
 
 
 def test_multicolour_print_books_each_roll(env):