substantivity

Substantivity refers to the attraction between a substance, such as a dye, and a fiber. Dyes are substances used to impart color to materials like textiles, paper, and leather, with the color resisting alteration from washing, heat, or light. Historically, dyes were derived from natural sources like plants and insects. However, synthetic dyes, largely developed from coal tar byproducts, began to dominate the market by 1900 due to their brightness, stability, wider color range, and lower cost compared to natural dyes. The color of a dye is determined by its molecular structure, specifically the presence of conjugated double bonds and groups called chromophores and auxochromes. Direct dyes, or substantive dyes, are applied from a hot aqueous solution, allowing them to penetrate the fabric's microstructure.123456