Abstract: A pigment composition obtainable by dry-milling an organic pigment in the presence of a resin for a printing ink, the resin being composed of a synthetic resin for a printing ink in an amount of 10 to 80 parts by weight per 100 parts by weight of the organic pigment and an aliphatic hydrocarbon resin which is extracted from gilsonite and has a softening point of 120 to 125° C. in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the organic pigment.

Abstract: A pigment composition obtainable by dry-milling an organic pigment in the presence of a resin for a printing ink, the resin being composed of a synthetic resin for a printing ink in an amount of 10 to 80 parts by weight per 100 parts by weight of the organic pigment and an aliphatic hydrocarbon resin which is extracted from gilsonite and has a softening point of 120 to 125° C. in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the organic pigment.

Abstract: A stamp ink, for stencil printing, is made from a coloring-agent mixed in a vehicle made from resin and oil-based solvent. The stamp ink has a viscosity in a range from 20 to 250 poises at a shear rate of 20/sec under temperature of 25.degree. C. and has a thixotropy index T.I. in a range from 1.2 to 3.0 under temperature of 25.degree. C. where the thixotropy index T.I. is defined in the expression of: T.I.=(Viscosity at a shear rate of 0.5/sec)/(Viscosity at a shear rate of 5.O/sec).

Abstract: An azo pigment composition which forms a dispersion having high tinting strength and excellent clearness, transparency, fluidity and storage stability, and which is formed from a coupling reaction between a diazo component and a coupler component, and contains a compound represented by formula (I) ##STR1## wherein Q represents a diazo or coupler component moiety, A represents a divalent bonding group selected from a class consisting of --CONR'--, SO.sub.2 NR'--, --CH.sub.2 NH-- and --CH.sub.2 NHCOCH.sub.2 NH-- in which R' represents a hydrogen atom, alkyl group having 1 to 20 carbon atoms or aryl group,each of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 represents a hydrogen atom, alkyl group having 1 to 20 carbon atoms or alkenyl group having 2 to 20 carbon atoms, and R.sub.3 and R.sub.