itago 板子

An Edo period term for wooden planks with a rectangular cross-section, between 5 cm and 30 cm thick. These planks were cut into thinner timbers for use as ceiling boards, and for doors and shutters. If a plank was 50 cm wide or more and was at least 18 cm thick, it was called atsu itago 厚板子. If it was less than 42 cm wide and less than 12 cm thick, it was called ko itago 小板子. The forests of Mt. Kiso, Kisodani 木曽谷; located mid-way between Tokyo and Kyoto, about 130 km from Nagoya, were a major source of itago. It is believed that the word shishiryō 宍料 used in the Kamakura period, had the same meaning as itago. Synonyms for itago vary according to the region but bangi 盤木 and hiramono 平物 are among the best known.