Investigation of three colour inks was performed using the HPLC method. The research is based on the theory of reducing of solvent in ink and on the change of ratio between dyes due to the degradation of the dye or changes of its extraction properties. Old samples, aged from 1 to 7 months were selected for research. Samples were made using blue, violet and black ballpoint ink. Record samples are kept in the dark, in climatic conditions of a usual office. During the identification of ink compound, by using LC/MS, a statement was made that each ink sample contains 2-phenoxyethanol as a solvent, Methyl Violet and Basic Blue dyes and their degradation products. The areas of peaks gained at characteristic wavelengths are used for the analysis of the aging process.