Buckram is a stiff cotton (occasionally linen or horse hair) cloth with a plain, usually loose, weave, produced in various weights similar to muslin and other plain weave fabrics. For buckram, the fabric is soaked in a sizing agent such as wheat-starch paste, glue (such as PVA glue), or pyroxylin (gelatinized nitrocellulose, developed around 1910), then dried. When rewetted or warmed, it can be shaped to create durable firm fabric for book covers, hats, and elements of clothing.

In the Middle Ages, "bokeram" (as the word was sometimes spelt in Middle English) designated a fine cotton cloth, not stiff. The etymology of the term remains uncertain; the Oxford English Dictionary considers the commonly-mentioned derivation from the name of the city of Bokhara unlikely.