noun
oblong binding
A bookbinding style where the binding is on the shorter side, resulting in a landscape-oriented book. Common for albums, sketchbooks, and some technical documents.
このアルバムは横綴じなので、写真が大きく見やすい。
This album is oblong-bound, so the photos are large and easy to see.
横綴じのノートは、横向きに使うのに便利だ。
Oblong-bound notebooks are convenient for landscape-oriented use.
縦綴じ refers to portrait-oriented binding (binding on the longer side), while 横綴じ is landscape-oriented.
Compound of 横 (yoko, 'horizontal') and 綴じ (toji, 'binding').