This is just wicked cool. Apparently, in the 1950s, Russians would record bootleg copies of music banned by the Soviet Union on used X-ray film. Western music ranging from jazz to boogie-woogie to rock-n-roll was popular. At the time, vinyl was rare and tape recorders weren't readily available, so X-ray film was a viable and ingenious option.
Aesthetically, these records have that timeless cool appeal that comes with anything related to counterculture and the underground music scene. This vibe is also exuded in their gritty, history-laden sound.