Gelatine and Dye Fixation

Abstract

The design of a receptive coating for ink jet printing is highly demanding. Many parameters concerning quality of the print, dry time of the ink and light stability have to be taken into account. Most of the parameters are not independent, but influence each other. One of these important factors is dye fixation. Ingredients, which improve dye fixation often affect light stability and image quality as well. The dye fixation of pure gelatine coatings for ink jet purposes has been investigated. We measured dye fixation of different gelatine types. Acid processed and alkaline processed as well as a chemically modified type have been compared in a standard test. Remarkable differences have been observed. Dye fixation for the acid processed type is much better than for the two other gelatine types, which we have investigated. We also detected a dependence of dye fixation on the pH of the coating solution. Regarding this parameter dye fixation is better for pH 5 than for pH 8. These results have been assigned to the different IEP of the various types. The dye fixation has been compared to a commercially available, high quality, non gelatine ink jet paper. It was found that dye fixing ability of the acid processed type is in the same range than for the commercial paper.