A novel method to determine register variation of a press by a densitometry tool

Abstract

The print quality of a printing machine highly depends on good register variation values. The measuring of register variation is very important for putting a multicolor press in operation or for its repair and service. The manufacturers of print presses also need the evaluation of register variation to develop new products. The current industry standard method for measuring the register variation is based on image processing, which is a very expensive method. It was a great demand to determine the register variation by an alternative and affordable technique. In the present paper we introduce a new method to determine the register variation based on densitometry. In order to create a new method, a special color test target has been designed. The input of the method is the densitometric measurement values, and its output is the register variation value. The results of the method have been compared with those of an image processing method and the correlation coefficient between the results is almost 0.9. Since in the proposed method only a densitometer is needed, it can be considered as a very inexpensive alternative to the image processing methods. The results were also demonstrated to different specialists of a manufacturer of print press and received very positive feedback.