A process for preparing nanoscale particles of benzimidazolone pigments, comprising: providing one or more organic pigment precursor to a benzimidazolone pigment, providing a solution or suspension of a sterically bulky stabilizer compound that associates non-covalently with a benzimidazolone moiety on one of the pigment precursors, wherein the sterically bulky stabilizer compound is selected from the group consisting of alkylated benzimidazolone compounds, alkylated derivatives of aromatic acids, and mixtures thereof, and carrying out a coupling reaction to form a benzimidazolone pigment composition, whereby the pigment precursors are incorporated within the benzimidazolone pigment and one or more functional moieties on the benzimidazolone pigment is non-covalently associated with the sterically bulky stabilizer, wherein the sterically bulky stabilizer compound is selected from the group consisting of compounds of the following formulae: where X represents a linking group selected from the group consisting of amide groups (-NH-(C=O)-) and (-(C=O)-NH-), amine groups (-NH-), urea groups (-NH-(C=O)- NH-), carbamate or urethane groups (-NH-(C=O)-O-) and (O-(C=O)-NH-), ester groups (-(C=O)-O-) or (-O-(C=O)-), groups of the formula, and groups of the formula, wherein the symbol n of a diazo moiety DC n in the above formulae refers to DC 1 to DC 7 and wherein the asterisk (*) indicates the point of attachment to the amino group (-NH 2) in the diazo precursor structure, as well as the point of attachment to the azo functional moiety (-N=N-) in the final pigment structure, where each of R 1, R 2, and R 3 independently represent H or substituted or unsubstituted alkyl groups, provided that at least one of R 1, R 2, or R 3 represents H; where at least one of R1 to R6, represents-COOH or -CONH2, and at least one of R1 to R6 is hydrogen, and provided that at least one of R1 to R6 represents a sterically bulky functional group selected from the group consisting of groups of the formula -COOR, -NHCOR, - OR, and -CONHR, where R is a substituted or unsubstituted alkyl group, including linear, branched and/or cyclic alkyl groups of 1 to 100 carbon atoms, as well as linear or branched alkyleneoxy chains; and wherein the nanoscale pigment particles have an average particle diameter as derived from transmission electron microscopy imaging, of less than 150 nm. providing one or more organic pigment precursor to a benzimidazolone pigment, providing a solution or suspension of a sterically bulky stabilizer compound that associates non-covalently with a benzimidazolone moiety on one of the pigment precursors, wherein the sterically bulky stabilizer compound is selected from the group consisting of alkylated benzimidazolone compounds, alkylated derivatives of aromatic acids, and mixtures thereof, and carrying out a coupling reaction to form a benzimidazolone pigment composition, whereby the pigment precursors are incorporated within the benzimidazolone pigment and one or more functional moieties on the benzimidazolone pigment is non-covalently associated with the sterically bulky stabilizer, wherein the sterically bulky stabilizer compound is selected from the group consisting of compounds of the following formulae: where X represents a linking group selected from the group consisting of amide groups (-NH-(C=O)-) and (-(C=O)-NH-), amine groups (-NH-), urea groups (-NH-(C=O)- NH-), carbamate or urethane groups (-NH-(C=O)-O-) and (O-(C=O)-NH-), ester groups (-(C=O)-O-) or (-O-(C=O)-), groups of the formula, and groups of the formula, wherein the symbol n of a diazo moiety DC n in the above formulae refers to DC 1 to DC 7 and wherein the asterisk (*) indicates the point of attachment to the amino group (-NH 2) in the diazo precursor structure, as well as the point of attachment to the azo functional moiety (-N=N-) in the final pigment structure, where each of R 1, R 2, and R 3 independently represent H or substituted or unsubstituted alkyl groups, provided that at least one of R 1, R 2, or R 3 represents H; where at least one of R1 to R6, represents-COOH or -CONH2, and at least one of R1 to R6 is hydrogen, and provided that at least one of R1 to R6 represents a sterically bulky functional group selected from the group consisting of groups of the formula -COOR, -NHCOR, - OR, and -CONHR, where R is a substituted or unsubstituted alkyl group, including linear, branched and/or cyclic alkyl groups of 1 to 100 carbon atoms, as well as linear or branched alkyleneoxy chains; and wherein the nanoscale pigment particles have an average particle diameter as derived from transmission electron microscopy imaging, of less than 150 nm.