A gatefold or foldout is a type of fold used for advertising around a magazine or section, and for packaging of media such as in the phonographic industry.
A gatefold cover or gatefold LP is a form of packaging for LP records which became popular in the mid-1960s. A gatefold cover, when folded, is the same size as a standard LP cover (i.e. a 12½ inch, or 32.7 centimetre, square). The larger gatefold cover provided a means of including artwork, liner notes, and/or song lyrics which would otherwise not have fit on a standard record cover. It became famous as an extension of progressive rock, as the expansive, transient gatefolds by artists such as Roger Dean, H. R. Giger, or Hipgnosis became associated with concept albums.
Gatefold sleeves were also frequently used when an album contained more than one record, with Bob Dylan's 1966 double album Blonde on Blonde being the first multi-LP album to be released in a gatefold. Typically, double albums would feature one disc in each half of the cover, with larger albums either placing multiple LPs in one or both sleeves or using larger gatefolds. While some multi-LP releases (particularly those released during the vinyl record's market dormancy from 1988 to 2007) would either package the discs in a simple sleeve or sandwich the records between two cards and shrinkwrap, the prominence of gatefold for multi-LP albums led it to become the most common form of packaging for them.
Starting in the early 1950s, RCA used gatefold packaging for some of their deluxe 45 RPM single releases, such as Nat King Cole's 8-song "Unforgettable" EP with two 45s, released in 1952. Gatefold packaging for LPs was popularized in the late 1950s by band leader and stereophonic studio recording pioneer Enoch Light, so he could fit liner notes he had written describing the sounds in each song on the album sleeve. Disagreement exists as to the identity of the first gatefold LP packaging used with a traditional 33⅓ LP.
In other publishing
Gatefold ads and highlights are often used as extensions of the covers of publications, folded either outside to overlap the cover or inside to unfold when the cover is opened. Similar folds include the split gatefold and the spadea.