Flexography is a type of relief printing which began to develop rapidly at the end of the last century when it became less financially demanding and time consuming. Since than flexography has become primary printing technique for packaging material. The properties of the polymer printing form significantly affect the properties of the print. To make print quality better it is needed to adapt the printing form to get the highest quality print on the printed media. In this paper, the properties of the photopolymer printing form are considered. The goal of this paper is to produce a printing form made out of liquid photopolymers and to study the influence of the main exposure time on the mechanical and surface properties of the printing form as well as the influence on the formation and quality of the printed thin lines. Printing forms are made with UV radiation. The duration of main exposure directly influences the properties of printed thin lines, surface free energy, and hardness of the printing form. By changing the duration of the main exposure, printing forms and printing elements of different properties are obtained. The results of this paper can be taken as a guide to adapting the printing form to obtain the highest quality print on flexographic printing.