Mini album

A mini-LP or mini-album is a short vinyl record album or LP, usually retailing at a lower price than an album that would be considered full-length. It is distinct from an EP due to containing more tracks and a slightly longer running length. A mini-LP is not to be confused with the unique to Japan "mini LP sleeve" or "paper jacket" CD.

Mini-LPs became popular in the early 1980s with record companies who targeted consumers who were reluctant to buy full-length and full-priced albums. Several mini-LPs had been released in the late 1970s, including John Cooper Clarke's Walking Back to Happiness, which used the 10-inch format. The format was usually 12-inch or 10-inch vinyl, with a playing time of between twenty and thirty minutes, and around seven tracks. They were often used as a way of introducing new acts to the market or as a way of releasing interim albums by established acts between their main albums.Epic Records introduced the 10-inch Nu-Disk format in the early 1980s but they found it difficult to merchandise, and 12-inch mini-LPs became more common. Notable mini-LPs of the early 1980s included U2's Under a Blood Red Sky, which reached number 2 on the UK Albums Chart in 1983, and The Honeydrippers' Volume 1, which reached number 4 on the Billboard 200 in 1984.

Independent record labels often released mini-LPs by artists before releasing full-length albums. In 1987, 4AD took this approach with both Pixies Come on Pilgrim debut and the second album by Throwing Muses, The Fat Skier.

...
Wikipedia