Aurora: Colour Separation with PostScript Devices
T. Graham Freeman · 1994
Summary: For material to be offset printed, the masters need to be prepared as colour separations, one for each coloured ink. Production of the masters is a time consuming task, often performed by hand. A method is proposed to enable separations to be automatically prepared if the source material is available as a colour PostScript file. The method uses any black-and-white PostScript printer, and two header files, the first defining procedures to be used in preparing the separation, and the second selecting the colour of the separation desired. The method works with any colour Level 1 PostScript documents. Background Offset printing in colour is most frequently achieved by separately printing the chosen inks onto the final piece of paper. Separate plates are made up for each of the colours, and they must be carefully aligned or registered to reproduce the desired combination of colours. If you have an original illustration or manuscript in colour, the printer must manually separate the colours into the separate plates for reproduction. This is a slow and expensive process. Printers prefer to be given the originals already separated into the component colours. If you are producing the material on a computer for later reproduction by offset printing,