Many moons ago when I was a young man I produced my own music fanzine, a very crude publication that consisted of photocopied A4 sheets stapled down the left side. Getting each issue onto the streets was a lengthy chore that saw me painstakingly type out interviews and articles on a huge manual typewriter. I would then hand the completed typing over to my mother, who took it to work to have the text reduced on a photocopier. Finally I would lay out the pages, creating headlines using lettering transfer kits and sticking down blocks of text and photographs when I was happy with their positions. This was a tricky operation on which the visual impact of the fanzine depended as back in those days cut and paste meant scissors and a glue stick and once something was stuck down it was pretty much permanent.

With my interest in publishing aroused, I enrolled on a Desk Top Publishing course at night school to see what advantages there were to be had in computerised page layout and boy was it an eye-opener. I was introduced to Microsoft Publisher and such wonders as scanned images, changeable font sizes and wraparound text. It was all a world away from the prehistoric methods I had been using; it was like stepping off a penny-farthing and onto a jet ski.

More recently my employment saw me editing full colour glossy magazines, which was about as far removed from my old fanzine as could be. During my time here I worked closely with our designer who introduced me to a very important factor when producing documents that are intended for the printing press: converting from RGB to CMYK.

The way colours are represented on screen is called the colour space, and RGB produces images using combinations of Red, Green and Blue, the three primary colours of light. RGB is used to display on-screen images, so obviously as the document you produce in Publisher will be created on-screen, the application defaults to RGB and, if the document is destined to be viewed only as an on-screen image, as a web page for example, then you should remain in the default RGB. However, if your work is intended for a commercial printing press, then it needs to be converted to CMYK.

CMYK consists of the three primary colours of pigment, Cyan, Magenta and Yellow. Although technically these three colours can combine to produce black, in practice this tends to be of inferior quality and so a separate black ink is used, which takes the letter K, (from blacK.) This is the colour space to use if your Publisher documents are to be printed, and it is termed the 'four-colour process' or 'full colour printing'.

There are some colours in RGB that cannot be reproduced in CMYK. In these instances a close match is made, but this can still be quite different from what is in your original artwork. It is a good idea, therefore, to convert to CMYK before you make your design if the finished product is intended for the printing press. If you produce a document in RGB that you send to the printer's without converting, the results can be considerably different to what was created on-screen. Colours can appear pale and a country mile away from their RGB counterparts. Ten thousand wrongly coloured flyers is an expensive mistake to make, but a good printer will be happy to explain the process to you in detail and offer help along the way.

To convert from RGB to CMYK in Publisher, either an existing or new document, go to Tools/Commercial Printing, Tools/Colour Printing, and select Process Colours CMYK.

A final point is that all images included in the layout should be linked, not embedded, if CMYK colour space is to be maintained. You can create a link by going to Tools/Commercial Printing, Tools/Graphics Manager, where you should highlight the embedded image. Click Link, then Browse in order to find the original file and link to it.

A fairly complicated business, but definitely worth the effort as the results will more closely match your original document. No such complications intruded into the editing of my early fanzine, where CMYK could have stood for Cheap Magazine You Knock-up.