How to Spot a Fake Portofino Midsize 39
The IWC Portofino in the 39 mm case is one of the most copied dress watches on the market. Most fakes fail four checks: case thickness, dial text spacing, crown profile, and caseback engraving depth. Measure the case first, then read the dial under magnification. Those two steps separate the majority of copies from the real thing before you ever open the back.
One naming note before you start. IWC sold a Portofino Midsize in a 37 mm case, and a separate Portofino Automatic in 39 mm. Listings that blend the two names onto one 39 mm watch are common, so confirm the reference number on the caseback instead of trusting the title.
What you need
- Digital calipers that read to 0.01 mm
- A 10x loupe or a macro lens
- A bright, angled light source
- Photos of a known genuine example from an authorized dealer listing
- A soft cloth and a small screwdriver for strap changes
Checks, in order
- Measure the case across the widest point, crown excluded. A genuine 39 mm Portofino lands within a few hundredths of 39.00 mm. Copies commonly measure 39.4 to 40.2 mm.
- Measure case thickness from the caseback center to the crystal top. The genuine watch sits near 9.3 mm. Fakes run thick, often past 10 mm, because the movement spacer adds height.
- Turn the crown between two fingers. The genuine crown has fine, evenly cut knurling and a clean signed face. Copies show shallow teeth, a soft logo, or tool marks on the flanks.
- Set the watch under the loupe and read the dial text. Genuine printing is crisp with tight, even letter spacing and full ink coverage. Fakes smear at the edges, space letters unevenly, or use serifs that are too heavy.
- Study the applied indices and hands. Genuine markers have sharp, mirror-cut facets with no adhesive squeeze-out at the base. Copies show rounded edges or a visible glue ring.
- Check the date aperture. Genuine window edges are beveled and polished, and the date font is thin with square terminals. Copies show a raw stamped edge and a fat, rounded font.
- Flip the watch and read the caseback. Genuine engraving is deep with crisp walls, and it carries a correct reference number plus an eight-digit serial. Copies engrave shallow, with soft edges and mismatched reference numbers.
- Open the back if you can. The genuine calibre 35111 is based on a Sellita SW300-1 running at 28,800 vibrations per hour with about 42 hours of reserve. Copies usually hide a decorated Miyota or an unbranded Chinese movement with rough rotor engraving.
- Inspect the strap and buckle. Genuine alligator has irregular scale size and a signed pin buckle. Copies use embossed calf with uniform scales and a blank or blurred buckle.
- Verify the serial. Give the number to IWC service or a dealer and ask them to confirm the reference and production range.
Checks that settle it on their own
- Case thickness over 10 mm
- Reference number that does not match the dial layout
- Serial number with fewer or more than eight digits
- Sapphire crystal with a purple or gray tint under a white light
No single check proves a watch is genuine. Three or four agreeing checks do. If you are spending real money, hand the watch to a watchmaker and pay for a movement inspection.