Boro ( Japanese: ぼろ ) are a class of Japanese textiles that have been mended or patched together. The term is derived from Japanese boroboro, meaning something tattered or repaired. As hemp was more widely available in Japan than cotton, they were often woven together for warmth. Hemp usage was necessitated by the fact that cotton, a tropical plant, could not be cultivated in cold areas such as the Tohoku region, especially the northernmost region of Aomori Prefecture. Furthermore, during the Edo period, fabrics made from silk and cotton were reserved for only a select portion of the upper class. Boro thus came to predominately signify clothing worn by the peasant farming classes, who mended their garments with spare fabric scrapes out of economic necessity. In many cases, the usage of such a boro garment would be handed down over generations, eventually resembling a patchwork after decades of mending.