How can there be anything more annoying than your ink cartridge running dry? It will never be at a time when you are printing off a recipe that you might use one day in the future or when you're copying a funny from the paper to send to someone. No, you never run out of ink at such times. Only when there is a really important letter you need to get out or a CV for the job of your dreams that has a closing date of today.

We all see the little box that pops up in the corner of our computer screen and we all click on the cross thinking it'll be ok and we'll sort it out next time or pick one up next time we're in town. And we always forget, or there's not enough money after the essential clothes and shoe shopping has been done. But it's always too late. It always waits until that moment when we really, really need it and then it dries up.

It's like that ink cartridge is just waiting for that moment. It's been getting thirsty for some time while we have been happily ignoring it and now it's payback time. Right when we need it, it gives up. There's nothing you can do about it. You know the shops are going to be shut when it happens and you try all sorts.

You remove your ink cartridge from the printer, shake it and hear that really annoying sloshing of ink in the bottom. Yes, there is ink in there but it won't let you have it. You've paid for that ink but you're not going to get to it. But still you try. You shake the ink cartridge and put it back into the printer hoping to fool the machine into thinking it's got a new one. You even press it in extra hard just in case it's a weight issue. All to no avail.

That ink cartridge is hanging onto the dregs and you are not getting another drop. It doesn't matter that you want to print only in black and don't need the yellow. It doesn't matter that you only need one more page. You ain't getting it. Yes, you may well have a separate black cartridge but it feels neglected. It wants all the colours and it's holding the black to ransom. No yellow ink cartridge, no black ink. It doesn't make sense but what in this life does?

So, you try fooling your machine. You, the sane, sensible grown up thinks that just on the off chance it might work you switch off your machine all cool, calm and collected. You walk away as if you didn't want it anyway and it's no big deal. Then you sneak back when it's not looking, switch on and press print. Just one more page, please!

No. It's a definite no. You can't have it until you replace the hardly ever used and not quite empty yellow ink cartridge. You can take it as personally as you like. You know you should have replaced it sooner and it doesn't matter how unfair it seems or how maddening it is, while there may be a drop left in the bottom, a drop that you paid good money for, you can't have it.

There is a reason for this. Manufacturers want you to buy more! Putting a set amount of ink in a set size ink cartridge makes you think that you are getting a reasonable deal. When you realise that you're not getting all that you paid for what can you do but buy another one. You could try a different manufacturer but you will find they all use the same tactic. They all want that extra sale. If you don't like it you can always go back to biro?