Dyes and Dyeing
Dyes and Dyeing, materials and processes used to give a permanent color to textiles, leather, fur, hair, paper, feathers, food, medicines, inks, and other substances. Dyes are used in virtually every industry. Professional and home dyeing of apparel and household decorations are practiced widely.
Stains and paints color only the surface; dyes, however, penetrate all the substance being colored and combine with it either physically or chemically. Once this happens, the dye cannot be completely removed from the substance. Nevertheless, dyes vary in their ability to resist fading from washing or dry cleaning, or from exposure to acids, alkalies, heat, or sunlight. Dyes with a strong ability to resist fading are called fast dyes.