I’ve been working with the freeware version of Cadsoft Eagle and learning how to make my own printed circuit boards, in preparation for a new work in the “Technology of Good Intentions” series: Average Clock. I won’t go into the details, but the workings involve an extraordinary amount of electronic circuitry, so I elected to design it in submodules, using very thin (.25 mm!) double-sided printed circuit boards. After etching, I coat the copper with tin, and the end result looks Soviet-military. I quite like it!