This is the second and final Blondie album to be produced by Richard Gottehrer. "Denis", a cover of Randy & the Rainbows' 1963 hit "Denise", was a hit all over Europe, reaching No. 2 in March 1978 in the United Kingdom, and also reached No. 19 in Australia. "(I'm Always Touched by Your) Presence, Dear" was the second single from the album, reaching No. 10 in the UK in May 1978. The song was written by the band's second bassist, Gary Valentine, shortly before he left for a solo career prior to the recording of Plastic Letters; his departure necessitated Chris Stein playing bass on the album, as well as guitar. During recording Blondie was still signed to their old label, Private Stock Records. The album peaked at No. 10 in the UK and has been certified Platinum by the BPI. The pink dress Debbie Harry wears in the cover art was designed by Anya Phillips.
Plastic Letters has been remastered digitally and re-issued twice: the first time by Chrysalis Records in 1994 with two bonus tracks, and the second in 2001 by EMI-Capitol with four bonus tracks. The latter issue features the earliest demo of the band's future hit "Heart of Glass", then known as "The Disco Song".