I used to lay out my own boards, decals and black crepe tape on pin-aligned mylar. There would be a padmaster (pads only) and a separate sheet for each trace layer. We sent it out to Lorry Ray in Mountain View to be photographed. They could also do cool ground plane tricks, all with wet photography. We'd send the film out to the fab house and expect to get it back.
I still have a few layouts around, to show the kids. It was labor intensive.
Big sound systems for movie theatres (a dying biz) and a new home 3D sound system.