@grahamdunning It's now so cheap and fast to get boards made to ridiculously high standards that few people make their own. JLCPCB is one popular supplier
It is possible to etch boards with ferric chloride. Blank boards are available with photo resist, and the mask can be printed on a laser printer.
It's also possible to mill the copper from a circuit board using a CNC machine tool, which can be quite small if it's only got to take a sliver of copper from a fibreglass board.