The flexi isc (also known as a phonosheet or sonosheet) is a phonograph record made of a thin vinyl sheet with a molded-in spiral stylus groove, and is designed to be playable on a normal phonograph turntable. Flexible records were commercially introduced as the Evatone Soundsheet in 1960, but were previously available in the Soviet Union as roentgenizdat or bones, underground recordings on x-ray plates.