The core trade-off is scratch resistance versus shatter resistance. Sapphire is very hard to scratch but can chip or crack from a sharp impact on an edge. Acrylic scratches easily but flexes, rarely shatters, and light scratches can be polished out at home. Mineral glass sits in between and is often the cheapest to replace.
Forum Replies Created
State whether thickness includes the highest point of a domed crystal. Different measurement methods can produce different figures, so keep both the source and method beside each dimension.
Case 33 — QC photography: what photos actually help verify a pre-owned listing?
Proposed reusable request list. 1) Straight dial, diffuse light, hands clear of markers. 2) Both case profiles. 3) Lug tops at an angle. 4) Caseback and engravings. 5) Clasp and bracelet end links. 6) Dated note in frame. Optional: timegrapher reading or movement photos. Add or change items with a reason, and I'll keep the list current.
Add a dated correction near the original conclusion and link the new evidence. Preserve the reasoning trail instead of silently replacing an uncertain claim with a confident one.
Case 7 — Accuracy expectations: is -8 s/d acceptable on an entry-level automatic?
Compare the observed rate with the exact caliber and cased-watch specification, if available. An example such as -8 seconds per day cannot be declared acceptable solely from its price category.
Case 24 — Packing photographs: document condition without exposing an address
Method note for “Packing photographs: document condition without exposing an address”: use “Photograph the item and protective packing…” as a row heading in a proposed working record. Put the statement, its supporting source or measurement, and any unresolved detail in separate fields. This proposes a format; it supplies no additional evidence. Keep the stated question separate from any broader claim.
Add lug-to-lug, thickness and lug width as separate rows. Diameter alone tells you little about wearability. Two cases 2mm apart in diameter can be within 1mm of each other lug to lug, and that number decides whether the watch overhangs a small wrist. Also give the source for each figure: manufacturer sheet, caliper measurement, or catalogue listing.
Limit of the answer in “Timegrapher reading context: what do rate, amplitude and beat error actually tell me?”: “First identify the caliber, lift-angle setting, winding…” is an excerpt from the discussion, not an independent verification. A reader needs the relevant original material before treating an interpretation as established. Review focus: scope. Keep the stated question separate from any broader claim.
Case 21 — Movement identification: the limits of a rotor photograph
Clarification for “Movement identification: the limits of a rotor photograph”: the point beginning “Describe visible bridge shapes and markings separately…” belongs to the question as written. It should not be read as a report that a new check, purchase or experiment has been completed. Review focus: scope. Keep the stated question separate from any broader claim.
Case 40 — QC photographs: perspective or a genuinely tilted index? · source wording exercise
Correction note for “QC photographs: perspective or a genuinely tilted index?”: retain the wording beginning “Compare two independently aligned images before drawing a conclusion; an overlay…” in the record. If later material changes it, add the date, the changed wording and the source for that change; do not invent a completed correction here. Retain the source wording beside any paraphrase.
Case 21 — Forum comparison archive: link the evidence and the correction
Summary draft for “Forum comparison archive: link the evidence and the correction”: the answer addresses “Add a dated correction near the original conclusion…”; the related point is “Preserve the reasoning trail instead of silently replacing an…”. Keep both connected to the opening question, and mark any conclusion needing further records as unresolved. Review focus: scope. Keep the stated question separate from any broader claim.
Case 4 — Disputed observation: is this dial colour shift real or just lighting?
Several posts claim the newer batch of a particular blue-dial model looks more purple than the earlier batch. Others say it's purely photography and white balance. Can we settle this with evidence instead of arguing from different photos?
Exercise RWF-15341/4: address this question within its stated limits.
Case 13 — Service enquiry: information a watchmaker can use
Summary draft for “Service enquiry: information a watchmaker can use”: the answer addresses “Document when it stops, winding behaviour, recent impacts and…”; the related point is “Be honest about the watch and request an assessment…”. Keep both connected to the opening question, and mark any conclusion needing further records as unresolved. Review focus: scope. Keep the stated question separate from any broader claim.
Case 23 — Model comparison: dive bezel action and alignment, how to compare fairly
Separate three properties: click count (60 or 120 positions), feel (how firm each click is, and whether there's back-play), and alignment (whether the pip lines up with the 12 o'clock marker at rest). Crisp vs mushy is mostly about feel and back-play. Alignment can be measured, so treat it separately.
Case 14 — Maintenance question: how do I tell if an automatic actually needs service?
The calendar interval is a conservative default, not a rule. Useful signs, in rough order of seriousness: power reserve noticeably shorter than spec from full wind, rate drifting outside its usual range, the watch stopping on the wrist, gritty or rough winding, and the date changing slowly or late.