Corsets are typically constructed of a flexible material (like cloth, particularly coutil, or leather) stiffened with boning (also called ribs or stays) inserted into channels in the cloth or leather. In the 19th century, steel and whalebone were favored for the boning. Featherbone was used as a less expensive substitute for whalebone and was constructed from flattened strips of goose quill woven together with yarn to form a long strip (Doyle, 1997:232). Plastic is now the most commonly used material for lightweight corsets, whereas spring or spiral steel is preferred for stronger corsets. Other materials used for boning include ivory, wood, and cane. (By contrast, a girdle is usually made of elasticized fabric, without boning.)