Computers: Printing presses the purse: Shopping for a printer? You soon will be, so William Gallagher compares the two processes on offer

YOU WILL pay for those neatly printed letters to the bank manager, the only question is when. And whether you mortgage the house upfront and get a laser printer, or commit your salary to buying inkjet cartridges each month.

You will have to decide, though, because soon after you buy your computer you either realise that you will need a printer too, or find that you have friends who need one and will harass you at parties for advice.

Money is the crudest way of deciding between printer types, but it is also spot- on - you get what you pay for. The technical differences between laser printers and inkjets - also called bubblejets - are real and potentially significant, but they boil down to the cost.

A black-and-white inkjet printer like Hewlett-Packard's 520 or Apple's Stylewriter II will cost you about pounds 200. The cheapest laser printers from those two companies are Hewlett-Packard's Laserjet 4L and the Apple Personal Laserwriter 300 at about pounds 500 each.

Your first thought may be that inkjets do not print as well as laser printers, but this is not quite true. At this price, laser printers produce the image of the page you are printing at 300 dots per inch and inkjets at 360dpi. In addition, inkjets work by squirting ink at the page and they smudge slightly, enough to have the dots run into each other and give the illusion of higher resolution because there are fewer jagged edges.

Laser printers charge each sheet of paper electrically and then the laser beam decharges certain areas, picking off the bits where you do not want ink. When toner is laid down on to the paper it sticks to the charged areas in one smooth operation. No charge, no ink. This difference in precision can make text look better on inkjets, but graphics look better on laser printers. And the output depends greatly on when you print. It is not that there is some witching hour, but you will notice a drop-off in print quality produced from an inkjet cartridge over time.

Inkjet models have problems with graphics which have large areas of solid black. When the pages come out, the black area is so saturated with ink that it looks sodden. It does not feel wet, but the page is bent out of shape and can look dreadful. Laser printers might not manage the strength of black in the picture, but you will not get that problem.

You also will not use up so much ink. The cartridges in inkjet printers are not expensive, costing about pounds 17 or so, but you get through them quickly. There are no definitive figures for the amount of use you will get out of a printer and ink supply, but Hewlett-Packard expects typical inkjet printer usage to be about 1,000 pages a month.

Depending on the type of work you print, you should budget to use at least one cartridge doing that. Laser printers, similarly, do not have figures for the number of pages you will get from the toner cartridges they use, but basic models are rated at about 8,000 pages a month. Toner cartridges cost about pounds 80. Again, depending on the type of page you print, you could use one a month.

But at that level, and especially if you go beyond these usage figures, the companies will return your askance look should anything break down. It is fairly easy to reach the inkjet's maximum page count, but not the laser one. So the inkjets will cost you more per page and will take a lot longer to print those pages.

Although the inkjet may seem the most obvious choice because of its cheapness, in practice you are often better off going for a laser printer because of the running costs. But pounds 300 is a big difference if you find that you only print out the odd letter every other month.

And if you ever fancy printing out in colour, do not go near laser printers. A year ago you would have had to pay pounds 16,000 for a colour laser printer. They have since come down to pounds 6,000 and upwards, although the image quality has not improved to the same degree. Photographic quality colour print-outs need a printer based on thermal wax technology, but, while available, these are far less common than inkjets or monochrome laser printers and tend to be expensive.

If you just need a blue logo or a red and green pie-chart, a colour inkjet printer will do the job very well and cost about pounds 270 to pounds 300. You get the same considerations about initial cost and then subsequent consumable prices, but the gap between the cost of colour inkjet and laser printers means there is no comparison.

There is an extra problem, specific to colour inkjets, and that concerns black- and-white printing. No matter what you buy the printer for, you will end up printing mostly in black and white: normal correspondence, invoicing and so on. Many colour inkjets produce black by mixing other colours and squirting the lot out at once. This makes more for a brown than a black, so the better system is where you have three colour ink cartridges and one separate pure black one.

There is also an argument for getting paper produced specifically for the printer you buy. All printers will print out on anything, but certain types of paper will look better and certain overhead projector acetate sheets will turn into molten plastic. Ask what the maker recommends you use. This will probably be more expensive: for instance, 200 sheets of A4 paper for a colour HP Deskjet 500C will cost you about pounds 18. Glossy paper can be pounds 35 to pounds 40 for just 50 sheets. No matter what you go for, it seems that they will get your money in the end.