Chêne du Japon

Harvesting takes place when acorns are ripe in late summer. After picking, the acorn cupules are dried. Then they will be grinded into powder and boiled. The decoction is filtered before being used. The paper sheets are soaked into the dye bath and allowed to dry. The color obtained is a brown tone ranging from beige to brown depending on the number of passes through the bath. It is possible to use various mordants to obtain other colors. Without mordant the color obtain is beige to brown; if the mordant is an ash lye or copper acetate, color is yellow-brow; if mordant is an iron salt, the color varies from gray to black.Dyeing of paper is performed in two ways: pulp dyeing (sukizome) or sheet dyeing (hitashizome by dipping or hikizome by brushing.

To dye paper by soaking, the sheets are plucked one by one between two wooden sticks by the small side. This will keep the sheet flat during soaking.

Usually three jars of dye are prepared with decreasing concentrations. The paper is dipped in the less concentrated dye jar and oxidation occurs in the air; the paper is then soaked in the little bit more concentrated dye. After oxidation, the sheet is dipped into the third jar with the strongest concentration. The process can be repeated several times to obtain a color more or less intense. The sheet is dried by exposing the surface to air; the color changes by oxidation.