Direct Dyes

Direct or substantive dyeing is normally carried out in a neutral or slightly alkaline dye bath, at or near boiling point, with the addition of either sodium chloride (NaCl) or sodium sulfate (Na2SO4) or sodium carbonate (Na2CO3). Direct dyes are used on cotton, paper, leather, wool, silk and nylon. They are also used as pH indicators and as biological stains.

Direct dye, also called Substantive Dye, any of a class of coloured, water-soluble compounds that have an affinity for fibre and are taken up directly, such as the benzidine derivatives.

Direct dyes are usually cheap and easily applied, and they can yield bright colours.

Wash fastness is poor but may be improved by after treatment. Most packaged dyes sold for home use are direct dyes.