Abstract: The aqueous dyestuff formulation of an tetrakisazo direct dyestuff which is stable to alkali and contains at least one aromatic hydroxyl group and/or enol group and at least one group conferring solubility in water, or a mixture of such azo direct dyestuffs, is characterized in that it has a pH value equal to or greater than 12 and is prepared by mixing an azo direct dyestuff which is stable to alkali, water and a tertiary alkali metal phosphate and/or alkali metal metasilicate and/or alkali metal hydroxide, and by choosing the proportions such that the dyestuff formulation contains 5 to 50% by weight of dyestuff and has a pH value equal to or greater than 12. The dyestuff formulation is used, after dilution with water, for dyeing and printing natural or synthetic materials containing hydroxyl groups.

Abstract: An improved process for preparation of a condensed product of phenothiazine and p-nitrosophenol which contains more than 60% by weight of indophenol S-oxide of the formula ##STR1## by condensing phenothiazine with p-nitrosophenol in sulphuric acid wherein the improvement comprises the phenothiazine being in 60 to 90% strength sulphuric acid at the time of addition of the p-nitrosophenol.

Abstract: Dyeing and printing with sulfur dyestuffs involves dissolving the dyestuff by reduction. The dissolved reduced dyestuff is applied to the material to be dyed or printed and the dyestuff is reconverted into in soluble dyestuff by oxidation. The present invention improves the prior art by using as the dyestuff reducing agent a compound of the formula ##STR1## or an alkali metal salt thereof, wherein R is --H or --OH and R' is --H, --CH.sub.3 or --CH.sub.2 OH.

Abstract: Green sulfur dyestuff is produced by reacting phenothiazine in sulfuric acid with an oxidizing agent, condensing the oxidized phenothiazine with p-nitrosophenol and thionating with sulfur and sodium sulfide the condensate in a bake or reflux process.

Abstract: Single bath dyeing of polyamide fibers and blends of polyamide and cellulose fibers with aqueous solutions of reduced sulphur dyestuffs containing, as a dye accelerator, compounds of the formula ##SPC1##Wherein:A taken separately is hydrogen, halogen, hydroxy or alkoxy or alkyl having 1 to 4 carbon atoms;B taken separately is --COOR.sup.1 or --Y--Z.sup.1 --M orA and B taken together are of the formula ##SPC2##Y is a direct bond, --0--, --S-- or --CO--;Z.sup.1 is alkylene having 1 to 4 carbon atoms or alkenylene having 2 to 4 carbon atoms;M is --COOR.sup.2 or ##EQU1## Z.sup.2 is hydrogen, halogen, hydroxy or alkyl or alkoxy having 1 to 4 carbon atoms;Z.sup.3 is hydrogen, halogen, hydroxy, alkyl or alkoxy having 1 to 4 carbon atoms or when B is --COOR.sup.1, Z.sup.3 may be --COOR.sup.1 ;R.sup.1 and R.sup.