The short answer
Three things sink most fakes: the case is too thick, the printing on the dial is soft, and the movement has no real hand finishing. A genuine Patrimony manual wind is an exercise in restraint. The classic 40 mm reference runs a hair over 6.5 mm thick, the dial carries almost nothing, and the money went into the parts you cannot see.
Start with the case profile
Run a thumbnail from the bezel down over the lugs. On a real one that transition is one continuous polished curve, and the lugs taper and bend down sharply where they meet the strap. Fakes tend to show a flat top surface, a visible step at the bezel edge, or lugs that look stuck on as an afterthought.
Measure thickness if the seller allows it. Anything near 9 or 10 mm is wrong for a manual wind Patrimony, since the whole point of the model is how little metal sits between you and the wrist. Case sides should be mirror polished with no tool chatter, and the lug tips should stay sharp under a loupe rather than rounded from a buffing wheel.
Read the dial like a printer
Look at the signature, the city name, and the Swiss Made at six o'clock. Strokes should be crisp and uniform in weight. Fakes give you letters that thicken in the middle, letters that touch, or a stray dot of ink. Applied indices should be solid gold, faceted, set dead straight, with edges you can feel. Glued-on or printed markers are a hard no.
Check the minute track. Dots should be perfect circles, identical in size, evenly spaced. On fakes they drift, vary in diameter, or sit slightly off the arc.
Hands and crystal
Baton or leaf hands are faceted and mirror polished, with a clean bevel down the center and no nib marks. Stamped flat hands with rough edges are the giveaway on cheap copies.
The sapphire should carry anti-reflective coating on the underside only. Tilt it toward a light source. A faint bluish or violet reflection is normal. Coating on both faces looks gray-purple and washes the dial out, and mineral glass scratches within weeks.
Crown, caseback, engraving
The crown is signed with the Maltese cross and sits flush against the case with no gap. Caseback engraving covers the reference, the serial, the metal purity, and the origin. Genuine engraving is cut with depth you can catch with a fingernail. Laser-etched fakes look shallow and slightly rippled. The serial on the caseback should match the one on the movement, and the reference should decode to a real Patrimony manual wind.
Open it. The movement is the tell
The thin hand-wound caliber inside runs roughly 2.6 mm thick with about 20 jewels, 28,800 vibrations per hour, and a power reserve near 40 hours. What matters more is the finishing. Bridges carry Côtes de Genève stripes. Every edge is beveled and polished, an operation called anglage. The base plate shows circular graining, and the screw heads are polished with chamfered slots. The bridges should be stamped with the maker's name, the city, the Maltese cross, and on certified examples the Hallmark of Geneva.
Now wind it. The feel is smooth with light, even resistance and no grinding or tinny clicking, roughly 25 to 30 turns from empty to full. A gritty, rattly wind usually means a cheap hand-wind or a stripped automatic underneath, and 21,600 vibrations per hour is a red flag on a watch that should run at 28,800.
Weight, gold, paperwork
An 18k case feels dense and stays cool against the skin. Gold-plated brass feels light and warms up fast. Ask to weigh it, and if you own a scale, compare against 15.5 grams per cubic centimeter for 18k. Then look at the paperwork: box, certificate, service history, matching numbers. A seller who cannot produce any of it is telling you something.
Checklist before you pay
- Thickness under 7 mm on the classic manual wind
- Continuous polished curve from bezel to lug tip
- Sharp, evenly weighted dial printing
- Applied gold indices, straight and faceted
- Single-sided AR coating on sapphire
- Cut engraving, matching serials
- Striped, beveled, properly finished movement
- 28,800 vph, smooth winding feel
- Box, papers, and a service record you can verify
One last thing
No guide replaces ten minutes with a watchmaker and a loupe. The better fakes photograph beautifully and fall apart on the bench, and the bench is where you want to find out.