Every device in your system has a ’colour space’ - that is, the range of colours that it can accurately reproduce. Colour spaces are typically mapped against a ’Colour Space’ called LAB - which represents every colour perceivable by the human eye. Consider a monitor screen - as a light-emitter it can produce quite a wide range of colours that ’glow’. Compare that with a typical print on paper; this can not produce as wide a range of colours, because it reflects light. Furthermore, certain qualities of the papers (or the inks, or the dyes or silver in the paper) will also effect what exact colours can be reproduced on this paper. Consider how different inks may have different abilities to reproduce colours, and how scanners or digital cameras have differing capabilities. Ideally, each device in your system will come with a ’profile’ that describes the capabilities of the device, and by using this profile the system can help immensely in translating a file from being suitable for one device to another device.

As different devices have different capabilities in reproducing colour, one of the facilities of Colour Management is to control how one ’colour space’ is converted into another. Remember, your graphics file will be in one colour space (often Adobe RGB 1998 or sRGB, but of course there are many to choose from), your monitor will be able to display a different range of colours, and your printer yet another range of colours. Where one colour space is smaller than another, there need to be functions to control how colours in one space are converted to another. These are the ’Rendering Intents’. Again, the Rendering Intents are documented more fully in Photoshop documentation... but for now we will just say that the ’Perceptual’ and ’Relative Colorimetric’ rendering intents are probably the ones most suitable for photographers and continuous tone images.

Please note that MWORDS has closed. We aim to retain these support pages in the hope that they may benefit our past customers, but regret that we can no longer offer further comment or support in relation to the information above.