noun
futon cover fabric; ticking
Refers to the durable outer fabric of a traditional Japanese futon, not the removable cover (カバー). Often made of cotton ticking.
布団皮が破れたので、新しいのに張り替えた。
The futon cover fabric tore, so I replaced it with new material.
布団カバー is a removable, washable cover that goes over the futon, while 布団皮 is the sewn-on outer fabric of the futon itself.
Compound of 布団 (futon) and 皮 (skin, outer layer). The reading がわ is a rendaku form of かわ.