A brown pigment, consisting of the finest part of wood-30ot, pulverized, and passed through a fine sieve, then mixed with a little gum-water, made into cakes, and baked. It is a fine transparent colour, and has much the same effect in water-painting, where alone it is used, as brown pink in oil. The best is prepared from dry beech wood, by grinding it with water into a smooth paste, then diluting it with more water. After the grosser liquor has subsided, the liquor is poured off, and left to settle for a few days; the fine matter that remains is the bistre.