The album is part of the vaporwave genre and features samples of Japanese television commercials from the 1980s, particularly those advertising airlines and holiday destinations. The album was produced between February and March 2013 and it was first envisioned as a sequel to Prism Genesis under the title "Transcontinent". The album can be streamed on her Bandcamp. In 2018, Sleepline was re-released on CD and vinyl.