Of a dye or pigment: that attaches itself directly to the stuff, without the necessity of using a mordant.

General attributive.

a red dye originally used to colour cotton without the use of a mordant, and now chiefly used as a tissue stain in microscopy.

Of a textile dye: able to be applied directly at approximately neutral pH.

Dye Chemistry. Applied to a group of basic azo dyes that contain a quaternary ammonium group, often with safranine as the diazo component, and…

Dye Chemistry. Designating certain dyes and mordants that are applied simultaneously in the same bath; relating to or using such dyes.

Of a dye: not requiring a mordant; = substantive, adj. 2c.

Of a dye: similar to indigotin in chemical structure, spec. in having another atom or atoms, esp. of sulphur, in place of one or both of the…

Chemistry. Of a dye or other colouring material: designed to react chemically with the substrate, usually in order to become fixed.

any of a class of vat dyes that are substituted derivatives of thioindigo and are used esp. in textile printing; also attributive or as adj.