A fake Jaeger-LeCoultre ref 344648 usually fails in three places: the reference number does not match the watch in front of you, the movement is not a JLC calibre, and the caseback engraving is too shallow or too crisp in the wrong way. If you only stare at the dial, you will miss all three. I check the paperwork and the movement first, then work backward to the cosmetics.
Confirm the reference before you judge anything else
Most bad watches are bad at the listing stage. Before you look at a single screw, find out what ref 344648 is supposed to be: the model line, case size, case metal, dial variant, and the calibre JLC fitted to it. A seller who cannot tell you which model the number belongs to is already a problem.
Reference formats also matter. Jaeger-LeCoultre has used different numbering conventions across eras, and modern references often carry a letter prefix and a trailing digit. A caseback stamp, a warranty card, and a hang tag that disagree on format or on the exact digits are a strong sign that someone assembled a watch around a number they found online.
Caseback and engraving
- Font and spacing should match JLC's house style for that era. Fakes tend to use a generic sans-serif with uneven letter spacing.
- Engraving depth is consistent on genuine cases. Replicas are often laser-etched, so the lines look sandy or slightly frosted under a loupe.
- The reference and the serial are different numbers. If a listing shows one number used as both, walk away.
- Check the transition between polished and brushed surfaces. Fakes blur that line, or polish areas that should be brushed.
Movement: the hardest thing to fake
This is where most counterfeits fall apart. A genuine JLC calibre shows hand-finished bridges, Geneva stripes with clean edges, polished screw heads, and chamfered angles you can see without magnification. Replicas built on an ETA or Seagull base usually show flat, matte finishing and screws that were never polished.
Two practical checks. First, the beat rate: many genuine JLC movements run at 28,800 vibrations per hour, and a counterfeit running at 21,600 will sweep visibly slower on a timing app. Second, the rotor engraving and weight. Gold rotors feel dense and cold; cheap plated rotors feel light and ring differently when tapped. Have a watchmaker open the case and photograph the movement before you commit.
Dial, hands, and crystal
Printing on a real JLC dial is sharp under a loupe, with no ink bleed on the brand name or the minute track. Applied markers sit flush and reflect evenly. Guilloché patterns repeat with machine precision, and any texture applied by hand stops where it should.
Hands should have polished bevels that catch light along the full length. Heat-blued hands show a deep, even blue, not paint. Check the crystal too: sapphire with proper anti-reflective coating nearly disappears at an angle, while fakes show a purple or green haze and heavy internal reflections.
Case, crown, and strap
Measure the case with calipers if you can. Fakes are often half a millimetre thick in the wrong direction, which throws off how the watch sits. The crown logo should be stamped deeply and centered, and the crown should engage cleanly with no grinding. On the strap, look at stitch density and thread color, and check the clasp engraving for the same font issues as the caseback.
Papers, box, and price
Warranty cards get copied. What does not get copied well is a coherent story: original purchase date, matching serial, service records, and a price that tracks the current market for that reference. If the number is a third of what dealers ask, assume the watch is wrong until proven otherwise.
Quick red flags
- Reference number that does not resolve to a real model, size, and calibre.
- Caseback, card, and tag that disagree on digits or format.
- Movement with no decoration, wrong beat rate, or a base calibre under the rotor.
- Dial printing that fuzzes under magnification, or painted instead of blued hands.
- Seller who refuses an opened-case photo or a third-party inspection.
None of these checks need a lab. A loupe, calipers, a timing app, and one honest watchmaker will catch almost every fake ref 344648 you are likely to meet.