Basketry material is a term used to describe the materials used to make baskets. OSIER (5 letters), osiers (6 letters), istle (5 letters) and raffia (6 letters) are all materials commonly used in basketry. OSIER is a type of willow tree, while osiers are the flexible twigs of the willow tree. Istle is a type of fiber made from agave plants, and raffia is a type of palm leaf fiber. All of these materials are used to create baskets of various shapes and sizes.