Have you ever worked out the cost of running your inkjet printer? It seems that the excitement of picking up printing technology on the cheap (PC World's current bargain comes in at under £25) blinds us to the brow-furrowing cost of ink cartridges.

I did my own sums to illustrate the point on our blog this week, and worked out that in 12 months – and I'm not a heavy user – I got through 14 branded cartridges, setting me back nearly £200. It's not a figure you'll see slapped on printers in the shops, but the true cost of an inkjet is hidden in a calculation involving the number of pages you're likely to print, and the life and cost of each cartridge. This isn't information we have at the point of purchase, so we usually choose inkjets over laser printers – which, of course, give more printouts per pound.

It's known as the razor-blade model; once you've made that small initial investment, you'll come back to the same company for essential parts for as long as you own the thing. And, as printers become absurdly cheap, the tactics used by printer firms to keep us buying branded cartridges become more cunning.

While other companies have always manufactured compatible cartridges (one reader, Phil Thane, recommended one such company called System Insight on our blog), branded cartridges often come with chips embedded so your printer knows when it's a "fake" and rejects it.

With the ink in a typical colour cartridge working out at over £8,000 per gallon, it's cheaper to have photographs printed via an online service. But, on our blog, Robin Parker mentioned a loophole offered by Cartridge World, a high-street chain specialising in refilling old cartridges. The chain has jumped through the legal hoops by replacing the cartridge's brand labelling with its own when they refill it – in effect, it is remanufacturing the thing. Managing director Jon Cullen boasts that one of his shops has refilled one particular customer's cartridge 41 times, saving him £1,600 – and saving the environment from a heap of little plastic boxes.

Diagnosis required

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