A technique for producing coloured patterns wherein carpet is first printed with colourless chemicals which alter the dye affinity of the printed areas. The printed areas in nylon carpet, for example, may be altered to be light dyeing and/or cationic dyeable relative to the untreated regular acid dyeable nylon. Subsequent piece dyeing in a dye beck with appropriate selected dyestuff s produces a coloured pattern. In this fashion numerous colour ways may be produced from a single print run.
