Cromalin
Cromalin ® is a dry color test method developed by DuPont that was introduced to the market in 1972. With the aid of the method, the color result of a print can be checked in advance (i.e. without having to be printed already). Such a preliminary check can be done by printing , analog proof or digital proof ; for the case of analog proof , Cromalin is the most common method. Cromalin color proofs can also be produced digitally.
To create the Cromalin proof, the exposures are carried out one after the other on sensitized photopolymeric film which is laminated onto special paper . Is started, then the lightest color yellow (Y] (green with cyan (C), it, magenta (M) for the mixed colors and orange), and finally, so that the deep drawing remains black (K). To this end, for each color a rasterized Color separation of the print original is created in the CMYK color model and these separations are exposed one after the other in contact. When exposed under UV light , the areas under the open, transparent areas are hardened by the light, the remainder covered by halftone dots remains unexposed, unhardened and therefore sticky The color powder of the corresponding color separation is then applied to this sticky layer and it sticks to the sticky areas. The excess residue is wiped off. A further thin film layer with the light-sensitive sticky coating is now laminated on top of this and the process is carried out again. As soon as the process for all 4 color separations, a protective coating is laminated on and one Exposure carried out without original, during which the entire surface is hardened and stabilized. In 1981 DuPont brought a coating machine onto the market for this purpose.
The results are color-accurate , lightfast and very close to the print result. Errors contained in the original template can be discovered and, if necessary, corrected before going to press .
This preliminary check of the print result is usually no longer carried out with this method, but with cheaper and faster digital proofs.
Web links
Individual evidence
- ↑ http://www2.dupont.com/Phoenix_Heritage/en_US/1972_b_detail.html DuPont Timeline: Cromalin 1972.