As a freelance writer I look into opportunities in a variety of formats that I think I may be able to achieve some success, including short stories, poetry and scripts. In the last of these, the submission guidelines will often demand that the script be typed in 12 point Courier font.

Courier, in case you didn't know, is a font in the style of an old fashioned typewriter. The reason that screenwriters are asked to use this particular font, however, has less to do with a nostalgic yearning for the typewriter, than sheer practicality. One page of A4 script typed in this manner will equate to approximately one minute on the screen, and so the writer knows that a sixty page script will roughly equate to a one hour film. I just did a quick experiment to test this and a 52 page script typed in 12 point Courier became a 46 page script when converted to 12 point Arial.

Not all fonts are chosen for practical reasons, however, and the font used can simply be a reflection of the image you wish to portray. Some companies choose a specific font to use in all documentation and its presence on a letter becomes as familiar as the letterhead itself. I worked for a firm that used 11 point Gill Sans MT for all communication and each computer in the office was set to use this font as default. If you would like to set your own default font in Word, it is a straightforward procedure.

In pre 2007 versions of Word, open a document in the 'Normal' template, then go to 'Format' and select 'Font'. In the 'Font' dialog box that opens, choose the font, style, size and even colour you want to adopt and then click 'Default'. This will bring up a prompt to verify that you wish to make the changes. Click 'Yes' and your new default font will be installed.

To change the default font in Word 2007, open the 'Home' tab and in the 'Font' group, click on the tiny arrow near the bottom right corner. This will open up the 'Font' dialog box and the steps are the same as above.

A light-hearted font, such as Curlz, looks great on party invitations, but it would be a disaster if you printed off your CV in it. Sober, reliable Arial is a popular choice for letters and CVs, but it would look rather dull on a flyer advertising a forthcoming carnival. Documents typed in the default Times New Roman are, unfairly I think, said to demonstrate a lack of imagination in the author (the default font was changed to Calibri in Word 2007).

And yet there appear to be some interesting statistics emerging from studies that suggest those harder to read fonts may actually increase the reader's ability to absorb the information.

One such study, carried out at Princeton University, printed off information about an imaginary alien species. This subject was chosen so that those partaking would encounter brand new words that had been made up especially for the experiment, of which they could have no prior knowledge. The group was split into two and one half were given information typed in 16 point Arial, black, while the other group were given the less legible fonts of Bodoni MT and Comic Sans MS, both in 12 point and 75% greyscale. The results showed that those who memorised the information printed in the more difficult to read fonts were able to recall, on average, 14% more than those who had studied the easier to read fonts.

Experts believe that the reason those reading the less legible fonts fared better in the experiment is that a difficult font requires more concentration and therefore the information is absorbed more thoroughly. If this proves to be true then it would open up many possibilities and we could see the nation's students printing off their research in all manner of wacky fonts on the eve of an exam, and then faring very well in it, apart from the guy who chose Marlett; he got an F.

Choosing a font that is suitable for a particular document is important, as it can make the difference between success and failure. Billy may be the life and soul of the party and a great wag in the office, but trying to demonstrate this by printing off his CV in Thickhead font would not cut much ice with prospective employers, and he would remain the life and soul of the Jobcentre for a while longer.