Chairs with a low seat and a tall sloping back, used as a prayer seat or stool; the form was seen in the 17th century, but became particularly popular during the Gothic Revival of the 19th century. For kneelers of similar form having a support for elbows and bookshelf, but not in the form of a chair, use "prie-dieus (benches)." For chairs with a very similar design, particularly those dating to the 18th century, but intended for use by females watching card games, use "voyeuses à genoux." Prie-dieu chairs may be made of humble materials, such as a wooden frame with a rattan seat-kneeler, or they may be upholstered; they may include a shelf for prayer books. They are found in private chambers and occasionally in churches. If they are part of a set, it is usually a bedroom set. Voyeuses à genoux are always upholstered, and are generally part of a larger set along with voyeuses intended for males to sit astride while watching card games.