What is "playtape"

PlayTape is a 1/8 inch audiotape format and mono or stereo playback system introduced in 1966 by Frank Stanton. It is a two-track system, and was launched to compete with existing 4-track cartridge technology. A PlayTape cartridge uses ⅛" tape. The cartridges play anywhere from eight to 24 minutes, and are continuous. Because of its portability, PlayTape was an almost instant success, and over 3,000 artists had published in this format by 1968. White cases usually meant about eight songs were on the tape.