Abstract: A composition comprising: (a) a cationic substance; (b) an acid generator; and (c) an alkyl or a hydroxyalkyl substituted starch. Also claimed is a polyamide textile material treated with the composition, a method for ink jet printing onto a polyamide textile material which has been treated with the composition and a polyamide material printed using the method.

Abstract: A method for the coloration of a substrate comprising ink jet printing a first and second set of inks onto the substrate wherein: (a) the first set of inks consists of one or more inks each of which independently contains a colorant selected from yellow, magenta, cyan and optionally black; and (b) the second set of inks comprises one or more inks each of which independently contains a dye selected from: a yellow dye of Formula (1) or salt thereof, an orange dye of Formula (2) or salt thereof, a red dye of Formula (3) or salt thereof and a blue dye of Formula (4) or salt thereof, wherein Formulae (1) to (4) are as defined in the description. Also claimed is a set of inks, ink jet printer cartridges, an ink jet printer and substrates printed using the printing method.

Abstract: A process for producing an image on a substrate comprising printing an ink onto the substrate, characterized in that the ink contains a reactive dye, the substrate is an acid paper and the printing is performed by an ink jet printer. Also claimed is an acid paper printed by means of the process.