I had a meeting with Thom Brown, who is one of HP's ink-jet gurus, today. Thom is making a bit of a name for himself via his [URL="http://www.youtube.com/printwiththom"]YouTube channel[/URL] - he's really quite amusing there.

Being a bit smug, I have to say I didn't really learn a lot from Thom today. He confessed that paper and ink technology, after several years of rapid development, hasn't changed much in the last three years or so, but a couple of things he said are worth highlighting.

If you have an HP printer that uses a permanent or semi-permanent print head (in other words the print head is not in the ink cartridge) it's possible that the ink you buy and use will have an expiration date. The printer may reject the ink after that date - even if the cartridge has been in the printer and used previously. Thom explains that after time the ink chemistry can change and this threatens the reliability of the print head. With printers that have disposable print heads built into ink cartridges this isn't a problem - you just load a new cartridge, but if your printer's permanent print head gets damaged, at worst your printer is a write-off.

The moral of this tale is that it may not be worth stocking up on ink if you aren't sure you will use it all within the expiration period.

On a different topic, HP is planning to change its Premium Plus photo paper range from the traditional 'swellable' surface coated type to the more commonly available porous surface photo paper type. The new Premium Plus photo paper will work with older HP ink jet printers that require this type of paper, but as these inks are protected from gaseous attack by the gelatine 'swellable' coating on the original paper, the new paper will mean your photos will not resist fading so well.

In this case, you may well indeed wish to stock up on the old type paper before it's phased out!