You would need to cut out and throw away the magnetic part if you are working on mechanical watches.
Apologies to all the watch making experts on here but for those learning and the tinkerers I thought I’d share this...
Soldering mat Large Size Magnetic Silicone Solder Pad 40x30 cm 500? Heat-Resistant Multi-Purpose Work Solder Station Pad for DIY Watch Phone Electronics Repair Grey https://www.amazon.co.uk/dp/B07KVQZ9...ing=UTF8&psc=1
Obviously for soldering but really useful as the parts of the watch are visible against the grey background, no fluff and easily stowed. The partitions are nice and low sided and a good number to keep the components together.
You would need to cut out and throw away the magnetic part if you are working on mechanical watches.