Summary

The world is full of colour, and there is no question that the trend in newspaper printing is clearly towards increased use of colour. Daily newspapers are offering special colours, also called spot colours, that are printed using only one single ink while the four colour pictures are printed by using the standardised four process colours, cyan, magenta, yellow and black. One problem is that a large number of spot colours results in the inconvenience and lack of economy of big stock. In addition, the printer is faced with the situation that there is a need to produce spot colours from process colours if there is no additional printing couple available. This project was initiated to answer the question whether spot colours can be produced by process colours. In spite of answering that question, this report gives the background information concerning calorimetry and it will demonstrate the colour space that is achievable by using process colours. Where are the spot colours situated in relation to the process colour space? What is the consistency over the print run ? The report includes also some printed samples concerning "the state of the art". The Pira Printing and Information Technology Division, U.K., was commissioned to carry out the project and its findings are presented in this Special Report.