Flexography is printing technique represented in many areas, mostly used for printing packaging. It competes with other printing techniques because it offers lower price, and the greatest advantage over other techniques is printing on different printing substrate regardless of the surface, if it is absorbent or non-absorbent. It's one of the high printing techniques that is using the hard and soft printing plates of rubber and photopolymer and quick-drying ink for printing. They are using water-based inks, UV and EB inks and inks based on solvents. Printing plates is in a direct contact with the material on which is being printed. In this paper I will theoretically explain the history and principle flexography, kind flexography units and plates for making flexo printing substrate and the colors used in the technique flexography. In the experimental part of the paper I will be comparing brightness CIE L * white ink on white and dark background depending on the producer and viscosity. By measuring the ratio of wet and dry matter of white ink I want to show the ink quality.