So you've got your paper profiled for your printer. You're using a digital camera that captures to a certain colourspace (for example let's say Adobe RGB). If your camera is pretty accurate with its colour capture, then you can be quite happy that a photo you capture will be printed correctly with true to life colours, or at the very least it's printing the colours that the camera has captured.

Unfortunately that's not the end of it. There's another device in the colour management chain that really needs to be calibrated. If you're going to be doing any image editing, then it's a very good idea to get your monitor calibrated (your camera or scanner can also be calibrated too, but that's a whole new subject, and with the accuracy of the latest digital cameras, it isn't the most critical in the colour management chain).

With a calibrated monitor, you will know that when you change a colour on the monitor, you are changing it to exactly the same colour in the image file. You will know that the resultant image is what you want, and that the image on your monitor will match the print from your printer. If you're going to send the image to anyone else, or if you're displaying it on the web, then you can also be certain that anyone looking at it will see what you see (providing their monitors are calibrated too!). This is very important if you're sending the image to a printing company or a publishing house, as your neutral print on your uncalibrated monitor might well result in an image with an obvious colour cast for everyone else.

Monitor calibration is not a one-off operation either. It should be done regularly, at least once a month and more often if colour accuracy is important to you. The colour accuracy of monitors changes over time, so you have to keep on calibrating.

So how do you go about calibrating your monitor? First of all, take a look at your monitor settings - can you alter the colour settings of your monitor? Along with contrast and brightness, you will probably have access to colour temperature and more often than not, access to the individual RGB settings of the monitor (sometimes stated as a "User" option on the colour temperature menu). The colour temperature has an effect on the white point of your screen. Usually you have a selection of defaults - around 9300K, 6500K and maybe 5000K. 9300K gives a blue (cool) cast to the white, whereas 5000K gives a yellow (warm) cast to the white. 6500K (or thereabouts) tends to be the most neutral, and is the default choice for sRGB image editing - it's best to set your monitor to this (many monitors will initially be set to 9300K).

Also, check to see if you have access to changing the individual RGB settings - if you do, then you can change the colours (which may also alter the brightness of the screen). It's best to leave these alone, and stick to the 6500K setting for now, but they can be useful later on for more advanced calibration.

Now that you've got the colour temperature set on your monitor, you've got a few choices as to how you're going to calibrate. They range from the free to the expensive, but as usual, you get what you pay for...

• Matching your screen to a print. This is the cheapest, and will get your monitor looking a little like your prints, but that's about it. You'll want to print out an image that has a lot of colours, ranging from the very dark to the very saturated. The best choice is a colour test chart which you can either do yourself, or download from the web. Some test images can be found here (I really recommend that you read that page too - it'll give you a lot more information on monitor calibration then this short introduction can). Now print the image out using a profiled paper to ensure your printed colours will match the original image, and then wait until the print is dry. Your print should now be a good match for the original image.

  You've now got the fun of altering the RGB settings of your monitor until the image on screen looks like the finished print. I'd recommend putting up your contrast and brightness to the maximum initially.

  If you've got a greyscale pattern (a chart of grey squares, going from black to white), then you can bring down the contrast and brightness until the pattern looks similiar to on-screen. Once you've done that, alter the individual RGB settings until the colours match roughly with your print (keep a check on the greyscale too, to make sure the brightness doesn't need re-adjusting).

  The result is a monitor that sort of matches your prints (or at least one of them!). The biggest flaw of this method is that it is based on a number of environmental factors such as the ambient light falling onto your screen, and the accuracy of your eyesight. In other words, it's not all that accurate. Factor in that monitors are not always that linear in the displaying of colours (particularly older ones), and you might be removing colour casts from one area and adding them in another. If you've gone to the trouble of getting a printer profile, we would recommend doing something more accurate...

• Using software calibration. Unfortunately there's not much out there apart from Adobe Gamma.

  Adobe Gamma is the most well know, and is a utility that gets installed if you have a copy of Photoshop or Photoshop Elements. It's more accurate than comparing a print to the screen, but it still suffers from the same drawbacks. Namely, ambient light falling onto your screen and your eyesight (if you don't use Photoshop or Photoshop Elements, then there's also the other drawback in that you can't purchase it seperately).

  Have a look at this guide to see how Adobe Gamma works. The software leads you through setting the contrast and brightness, and then the gamma. The one thing that takes it up a notch is that it creates an ICC Colour profile for your monitor based on your settings. This can then be saved and set as the default profile for your monitor, and will be used every time you use your computer. Altogether, it's an effective way to get a reasonable level of accuracy with a minimum of fuss. However, as with print matching, do note that if your monitor is not all that linear in displaying colours (such as with an older, or poorer quality monitor), then this software still cannot make any adjustments for this and you might well get colour casts in certain areas.

• Hardware Calibration. This is by far the best option for accurate colour matching, but it's the option that costs. You might find Adobe Gamma is good enough, and money spent on a hardware calibrator would not be worth it. However, if you are serious about colour management then hardware calibration is the route to take. Likewise, if the environmental factors that blight the past two options are a problem for you (light falling onto the monitor, and poor eyesight), or if your monitor is just not linear enough, then this is also the route to take.

  The hardware takes the form of a mouse like object, or a puck which either sticks to your monitor (for a CRT) or is suspending in front (for a TFT). The device works in tandem with the software. First of all you have to set up the monitor with the brightness and contrast. You'll then have to set up the colour of the monitor - this is where you usually have to set the individual RGB settings until they're all firing at the same rate. Once you've done that, the software then starts flashing different colours. The hardware device measures the colour that your monitor displays, and from this it can work out a colour profile.

  The process can take a few minutes to do. It's a pretty quick and painless operation, and the software is usually of a decent standard so that a complete novice can use it.

  The advantages of this are that it removes all the previous problems. Your eyesight is no longer an issue. Light falling onto the monitor does not affect it. Due to individual colours being measured, older or less accurate monitors will be compensated for in the profile, and the individual colour casts will be removed. With hardware calibration, you will have removed any guesswork from the whole process, which has got to be a good thing!

  So what is avaliable to you? There are a number of devices to choose from, particularly from the "big guns" of the colour management world - Monaco and GretagMacbeth. However, they're not cheap (£150-£200+). We would recommend another company with a very good reputation for providing cheap yet accurate calibration, and that is ColorVision with it's range of Spyder calibrators.