Abstract: A process for the production of resist prints under reactive dyes on textile materials which consist of cellulose fibers or a blend of cellulose fibers with other fibers, using reaction products of bisulfite adducts of aldehydes of 2 to 6 carbon atoms, or of ketones, with ammonia, primary amines or secondary amines in the molar ratio of from 3:1 to 1:1 as resists. Preferably, reaction products of a bisulfite adduct of acetaldehyde and ammonia in the molar ratio of from 3:1 to 1:1 are employed as resists. Because of the high stability of the resist print pastes, high color yields of the resist dye and satisfactory, reproducible resist effects of the ground dye are achieved.

Abstract: Concentrated dithionite solutions are produced by cathodic reduction of an aqueous solution, containing sulfite and/or bisulfite, which is circulated by pumping. The cathode and anode chambers are separated from one another by a permselective cation exchanger membrane. The catholyte must be circulated at least 10 times per hour and the selective catholyte volume outside the cell, defined asa = V.sub.total -V.sub.C /V.sub.total,Should be less than 0.9.