Album cover
An album cover is the front of the packaging of a commercially released audio recording product, or album. The term can refer to either the printed cardboard covers typically used to package sets of 10 in (25 cm) and 12 in (30 cm) 78-rpm records, single and sets of 12 in (30 cm) LPs, sets of 45 rpm records (either in several connected sleeves or a box), or the front-facing panel of a CD package, and, increasingly, the primary image accompanying a digital download of the album, or of its individual tracks.
In the case of all types of tangible records, it also serves as part of the protective sleeve.
Early history
Around 1910, 78-rpm records replaced the phonograph cylinder as the medium for recorded sound. The 78-rpm records were issued in both 10- and 12-inch diameter sizes and were usually sold separately, in brown paper or cardboard sleeves that were sometimes plain and sometimes printed to show the producer or the retailer's name. These were invariably made out of acid paper, limiting conservability. Generally the sleeves had a circular cutout allowing the record label to be seen. Records could be laid on a shelf horizontally or stood upright on an edge, but because of their fragility, many broke in storage.