When people used to press bootleg recordings onto X-Rays to pass around Soviet Russia

Brian Heater of TechCrunch has a fascinating post on his SubStack about "music on ribs" when people in Soviet Russia would rip audio onto discarded X-Ray printouts in order to share them with friends:

It's difficult to say whether Philo was first to discover that the soft, pliable nature of X-rays made them if not ideal, then at least suitable media for pressing records.