Process for pigmenting wood

A process for pigmenting wood, which comprises treating wood in succession:a) with a solution comprisingfrom 0.01 to 80% by weight, based on the solution, of a compound of the formulain which x is an integer from 1 to 8,A is the radical of a chromophore of the quinacridone, anthraquinone, perylene, indigo, quinophthalone, indanthrone, isoindolinone, isoindoline, dioxazine, azo, phthalocyanine or diketopyrrolopyrrole series which is attached to x groups B via one or more heteroatoms, these heteroatoms being selected from the group consisting of N, O and S and forming part of the radical A,B is hydrogen or a group of the formulaat least one group B not being hydrogen and, if x is a number from 2 to 8, the groups B being identical or different, andL is any desired group suitable for solubilization; andfrom 0.05 to 5% by weight, based on the solution, of a salt of the formulaorin which Kat is lithium, sodium, potassium or ammonium, An is formate, acetate, propionate or hydrogen carbonate, An is oxalate, maleate, fumarate, malonate, carbonate or hydrogen phosphate, and An is citrate or phosphate,in water or an organic solvent or in a single-phase mixture thereof,b) with a solution comprising from 0.01 to 50% by weight, based on the solution, of an organic C1-C6carboxylic acid in water or an organic solvent or in a single-phase mixture thereof, andc) converting the compound of the formula (I) thermally to a pigment of the formula A(H)x (V).