noun
flat; painted backdrop piece
A portable painted panel used as part of the stage scenery in kabuki and other traditional theater. Often a flat piece of scenery that can be moved or changed quickly.
歌舞伎では、書き割りを素早く入れ替えて場面転換を行う。
In kabuki, they quickly change the flats to switch scenes.
あの書き割りは江戸の町並みを描いている。
That backdrop piece depicts an Edo-period townscape.
Compound of 書き (kaki, 'writing' or 'painting') + 割り (wari, 'splitting' or 'dividing'), referring to painted panels that can be split or moved. The exact historical derivation is uncertain, but the term is firmly associated with kabuki stagecraft.