Evaluation of the influence of artificial UV ageing of printed images

Abstract

The main problems encountered in the long storage of printed or painted images are associated with deterioration of color characteristics and loss of information from them. The changes, that occur are due to the processes of ageing of the inks and papers. Natural ageing is a rather slow process. Therefore a study of the changes occurring with the printed images over the time under artificial UV radiation has been carried out. For the purpose of this experiment, was designed specialized test form, containing thousands of control patches for estimating the spectral, color and optical density shifts during the artificial ageing. The main goals of this research are to investigate the influence of artificial UV ageing on the optical density, spectral and color characteristics of printed images. The experiment have been performed in real printing conditions on state of art offset printing presses. The printing media used in the experiment are matte coated and uncoated offset paper, which are chosen because they are wide used all over the world. The test images and all the thousands of color control patches have been submitted to UV artificial ageing. The spectral and color characteristics of the inks and paper were examined during the different UV ageing period. The obtained results shows changes in all of investigated parameters during artificial ageing. The results are important from scientific and practical point of view. They might be used for modeling of ageing processes and could be very useful for recovering of original color characteristics of aged images.