Direct dye

Description

A large class of water-soluble dyes that quickly adhere to fibers without the aid of a mordant. Direct dyes were primarily used for dying cellulose and the grouping includes both natural dyes and synthetic dyes. Examples of natural direct dyes include henna, annatto, saffron, turmeric, and archil. Synthetic direct dyes, or substantive dyes, were first derived from aniline in 1884. In general, they give bright full colors when applied directly onto fiber in a neutral or slightly alkaline aqueous bath containing an electrolyte, such as sodium chloride or sodium sulfate. While direct dyes are typically applied to cotton, linen and paper, some work well with leather, rayon, silk, or wool. Because direct dyes generally possess poor colorfastness, some after-treatments, such as diazotization development, are used to improve washfastness. These include chelation with salts of metals (such as copper or chromium as well as treatment with formaldehyde or other dye-complexing resin. The after-treatments developers, however, can produce new chromophoric groups that change the base color of the dye. (For more information on developers, see naphthol, phenylenediamine, phenol, phenylmethylpyrazolone, or resorcinol).

Several structural types of Direct dyes include:

• Azo dyes: This is the largest class, often composed of sodium salts of sulfonate groups; examples are Congo red (DR28), Trypan Blue (DB14); DY142, DR1, DR3, DB1, DB8
• Stilbene dyes: known for bright colors; examples are Stilbene yellow (DY4), DY11, DO30, DR76, DBr78
• Phthalocyanine dyes: used for specific shades; some blue, cyan and green examples include DB86, DB87, DB199,
• Dioxazine dyes: primarily blue with good lightfastness and poor washfastness; Sirius Light Blue FFL (DB106), Remastral Violet FLR (DV FRL)

Direct dyes are also divided into the following classifications:

• Direct Fast Dyes: Pre-metallized compounds to provide improved light/wash fastness; Fast Yellow RSC (DY50, Fast Orange GGL (DO39), Fast Red F3B (DR80), Fast Turquoise (DB106)
• Direct Copper Dyes: These contain -OH groups that complex with coppers salts; Copper Blue 2R (DB151), Brilliant Blue BL (DB106), Green BLE (DG26), DG85, DBr126, DY49
• Direct Diazo Dyes: These directly bond to the fiber to deepen the color; Congo Red (DR28), Trypan blue (DB14(, Congo Brown R (DBr44), Dioazoraine Scarlet 5B (DR14)

See also Dye types.

Synonyms and Related Terms

substantive dye; direct dyes (pl.); colorante directo (Esp.)

Resources and Citations

• Judith H. Hofenk de Graaff, The Colourful Past: Origins, Chemistry, and Identification of Natural Dyestuffs, Archetype, London, 2004
• Hoechst Celanese Corporation, Dictionary of Fiber & Textile Technology (older version called Man-made Fiber and Textile Dictionary, 1965), Hoechst Celanese Corporation, Charlotte NC, 1990
• Rosalie Rosso King, Textile Identification, Conservation, and Preservation, Noyes Publications, Park Ridge, NJ, 1985
• Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982
• Thomas B. Brill, Light Its Interaction with Art and Antiquities, Plenum Press, New York City, 1980
• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 284
• Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
• Wikipedia: Substantive Dye Accessed May 2026