Kapa is a fabric found in ancient Hawaii made of beaten mulberry bark. It is similar to tapa found elsewhere in Polynesia but differs in the methods used in its creation. Kapa was used primarily for clothing like the malo worn by men as a loincloth and the pau worn by women as a wraparound. Kapa was also used for kihei used over the shoulders. Other uses for kapa depended on caste and a person's place in ancient Hawaiian society. Kapa bed covers were reserved for the ali'i or chiefly caste while kapa robes were used by kahuna or priestly caste.

Cultural anthropologists over the course of the twentieth century identified techniques in the creation of kapa that was unique to the Hawaiian Islands. The paper mulberry tree was cut and soaked in water then laid on a polished stone tablet and beaten by a hohua. After the first phase of beating, the kapa was transferred to a sacred house to be beaten a second time but in a religious manner. Each kapa manufacturer used a beater called an i'ekuku that left an impression in the cloth that was hers alone. After the European discovery of the Hawaiian Islands, Western traders travelled to Hawaii especially for kapa.