Chromos: A type of paper that is extra sensitive to reproduce the correct values of colors. The full name is Cromalin and is a brand name of the fa. Du Pont and is a photo-mechanical proof system developed in America. Since the system was the only usable system for a long time, the brand name was used in practice as the product name. The Maggi effect and also Spa red is one such example.
Broadly speaking, what Cromalin did was to make a color proof of the films of a 4-cl. Litho without, that you had to make image carriers (plates) and start printing on a proof press or production machine. So this saved an enormous amount of time and money.
From the beginning there was always a lively discussion, to what extent such an “imitation proof” would be a good prediction of the final print result. Later, more systems were developed, such as MatchPrint from 3M and Agfaproof from Agfa. All of which did the same thing. The funny thing is, people also kept calling the final products of these systems Cromalins.
Now, of course, all this has been superseded by digital techniques. Nowadays, one prints a high-quality full-color image of a picture on an ink-jet printer in no time. The printers are manipulated with special software to produce an image that is an excellent match for the final print result. One can then easily choose in the software a result in sheet-fed or web offset, or in gravure, or any other printing technique.