Also tsubushi 潰し. A plain background of a single color on a woodblock print *ukiyo-e 浮世絵, often used behind bust portraits *ōkubi-e 大首絵. Often described using the name of the color in question: kitsubushi 黄潰し (yellow ground), aitsubushi 藍潰し (indigo ground), or nezumitsubushi 鼠潰し (grey ground). A particularly luxurious variant of the technique, often seen on prints by Kitagawa Utamaro 喜多川歌磨 (1754-1806) and Tōshūsai Sharaku 東洲斎写楽 (act. 1794) from the mid 1790s, was to apply a coat of shiny ground mica, kira 雲母, usually on top of a color-printed background, kirazuri 雲母摺. Another variant was to print the background in a paler color while allowing the pattern of the woodgrain on the printing block transfer to the finished print. This was known as a woodgrain ground mokumetsubushi 木目潰し. It required considerable skill and effort to print an even coat in perfect registration *kentō 見当 on a background, especially in the case of darker colors. The color was not just printed once, but many times; and the paper was never completely peeled away from the printing block. Rather, only half of the sheet was lifted at onetime and extra pigment was added to the block as necessary. This technique of strengthening the impression by reapplying pigment to the block and reprinting was called kakenaoshi 掛け直し.