Ssarijambak is a kind of silkworm farming equipment used as support for a cocoon bed to rear silkworms. This silkworm-raising basket is also referred to as a rearing tray. A straw mat or paper is laid on the basket before breeding silkworms on it. Young silkworms can be accommodated on one basket, but as they mature, the number of baskets has to be increased due to space shortage. Multiple baskets would be laid in tiers on a rearing stand. The materials used to produce jambak include straw, bamboo and timber, and its shape is made by weaving the ribs in a grid or a lozenge formation onto a rectangular frame. Although the usual width and length of the basket are about 90 cm and 60 cm respectively, some baskets are larger than that according to the circumstances. Jambak were used together with a cocoon bed for silkworm breeding, but in general, a formed jambak was used for large-scale silkworm breeding as in the case of rearing silkworms for the royal family during the late Joseon Dynasty. Ordinary farmers used a mat woven with straws, reeds, or skinned hemp stalks instead of jambak.