gatefold
/ˈɡeɪtˌfoʊld/
noun
- A type of folded page or cover, especially in a book or record album, that opens out like a gate to reveal a larger image or additional content.
- The magazine featured a gatefold advertisement that opened to a full-page spread.
- I love the gatefold in this art book; it unfolds to show a panoramic landscape.
- The vinyl record came in a beautiful gatefold sleeve with photos of the band.