3505 IWC Ingenieur SL White ‘Graph Paper’ Dial

This is one of those rare occasions where a watch feels familiar, but isn’t. The ref. 3505 is an Ingenieur very like the ref. 3506, but, again, it isn’t. Both feature the desirable graph paper dial texture, but one is far less common. This, the 3505, was the very first iteration of the midsized Ingenieur. It has a Swiss only dial and debuted the then-new calibre 375 which was just 4mm tall. It was only produced for two years, in both an automatic and quartz offering. This is the elusive auto.


That calibre 375 was modified ETA 2892 base. Shortly after release, ETA debuted the new and smaller 2892-2, which led IWC to redesign a few details. Therefore, the reference numbers changed over as well. These earliest midsized Ingenieurs were the first to earn the nickname ‘skinny’, as they followed the 1832 Jumbo SL with a much thinner case. It’s not a vast difference to the latter 3506, but the first of anything has a way of becoming collectible all its own. It’s still water resistant to 12 atm, amag to 40000 A/m, and Germanic in design. But this Ingenieur blazed the path forward for a lot of fantastic historic offerings and that alone is worthy of underscoring.


The case here is relatively strong overall, but has seen a polish. Its dial shows small minor signs of spotting but nothing distracting. Indices and hands are lovely. It comes from a well-regarded German retailer.

Find this 3505 Ingenieur SL here from Watchurbia for 7900 EUR.