Flexi disc

Flexi disc recordings are a thin format designed to be playable on standard phonograph turntables. Before the advent of the compact disk, they were often used to include music with printed material such as magazines and music instruction books. A thin vinyl sheet could be molded with the recording and bound into the text with a perforated seam, at very little cost and without any requirement for a hard binding.

Bones are Soviet-era DIY punk flexi-discs, scratched into smooth sheets of plastic using a modified turntable. They are so called because one cheap, reliable source of suitable raw material is discarded medical x-rays, which have the added benefit of including ready-made and interesting images. This format was particularly attractive to politically suppressed punk rock music, since other publishing outlets were much less accessible.