Abstract: A process is provided for dyeing textile materials in a solid shade with a jet injection dyeing apparatus, including conveying means for transporting the textile, jet orifices for delivering dye to said textile material, and control means for supplying data to control the operation of the application of dye from the jet orifices to the textile material, which comprises the steps of: modifying the textile material prior to dyeing of same by applying to said textile material an aqueous admixture containing an effective minor amount of a thickening agent to maintain the viscosity of said aqueous admixture at from about 150 to about 750 centipoises, preferably about 200 to about 400 centipoises, to thoroughly wet said textile material; dyeing said textile material in a solid shade with an acid dye composition having a viscosity of from about 150 to about 750 centipoises, preferably from about 200 to about 400 centipoises, by applying said dye composition by means of said jet injection dyeing apparatus in an amoun