Production of images

Claim 1

An image producing system which comprises a substrate having printed on at least a portion of a surface thereof an ink having a pH of about 7, containing a liquid alkanolamine present in an amount sufficient to prevent reaction between the color former and the substrate on which the ink is printed and a color former of the formula I ##STR73## in which R 1 , R 2 and R 3 each represents hydrogen, halogen, alkyl, alkoxy, aryloxy, alkoxycarbonyl, dialkylaminocarbonyl, acylamino, acyl(alkyl)amino, ##STR74## in which Y 1 and Y 2 each represents alkyl or aryl, or in which Y 1 and Y 2 together represent an alkylene group; X 1 is hydrogen or an alkyl group, X 2 is an alkyl, cyanoalkyl or arylmethylene group or X 1 and X 2 together represent an alkylene group, X 3 is an alkyl or aryl group and n is 1 or 2, or of the formula II: ##STR75## in which Z 1 , Z 2 and Z 3 each represents hydrogen, alkyl, substituted alkyl, alkoxy, halogen, nitro, acylamino, aminoacyl or alkoxycarbonyl, A 1 and A 2 each represents alkyl or phenyl or A 1 and A 2 together with the nitrogen atom to which they are bound form a heterocyclic ring system and n is 1 or 2 and which system also comprises a carrier material impregnated with a solution of an organic acid in a weakly volatile solvent having a boiling point of a least 150° C and insofar as a color former of the formula II is used, the carrier is also impregnated with an azo coupling component.