Plastic Eternity features the first Mudhoney songs written with someone outside the band, producer Johnny Sangster, who appears on several tracks. Most of the songs on the album were not completely written prior to entering the studio, which is uncharacteristic for the band The album was written during the COVID-19 pandemic and recorded in nine days at the Seattle studio Crackle & Pop before bassist Guy Maddison moved to Australia. The album was promoted by the single "Almost Everything" and a world tour. Singles "Move Under" and "Little Dogs" followed.

April 7, 2023 was proclaimed Mudhoney Day by King County, Washington to coincide with the album release.[