A series of charts show the colors of commonly used fibers after reacting with important stains. These stains are divided into three groups: 1 Spot stains of ground wood reagents to detect the presence of mechanical pulp. Due to their limited value, they are not discussed further. 2 Iodine -- Iodide -- Metallic salt stains. The three most important of these are the Herzberg stain, the A and C stains. Preparation of these stains is described. 3 Aniline dyes. Used to determine the degree of cooking, bleaching, and purity of pulps. There are color plates for the bright stain, cooking stain, and Merritt stain. -- AATA