I like designing circuit boards. Over the winter, we (as in Skye Silver) were playing around with Celtic/Pictish key pattern designs and getting thoroughly fascinated with them. These are NOT your usual knotwork/interlace things, although they're vaugely similar. Anyway, having seen the sort of techniques available in PCB production (gold plating, solder mask, silk screen, routing etc.), I thought it would be really neat to make some drinks coasters featuring a key pattern design, made entirely with standard PCB processes.
Here they are. The design itself uses electrolytic gold plating over the copper, and a black soldermask on both sides. The board material is 2.4mm, which is thicker than the normal 1.6mm and makes it feel much more rigid. There's a non-slip cork backing, and I've made up a little card holder + plastic sleeve to present them in. They're 9cm diameter.
If you'd like to buy these (£10 each, free UK shipping, £3 worldwide shipping), head over to the IJ Instruments website.
Short waffly video: