Gti Bulk Ink

[wilko]

I'd say go for the OCP, they are probably the best quality and lowest priced inks available anywhere.
Can't speak for their inks for the Canon printers, but I've tried and been using those for Epson and they are the best in terms of gamut and fade resistance among IS (those mentioned in the post above), Inkrepublic and Inkjetfly...

If you need them in smaller quantities you can buy 250ml bottles here:
http://www.octopus-office.de/en/shop/l/c/printer-ink-canon-cli-8-pgi-5/

Thanks for link. I agree about OCP ink. It's great for Canon printers too. It's the best value I've found. I get it here in the UK:
http://www.promaximaging.com/

Unfortunately you have to order by telephone

However, OCP have suppliers in several countries - http://www.ocp.de/ but don't know if they are cheaper in Europe than Octopus

 

[costadinos]

However, OCP have suppliers in several countries - http://www.ocp.de/ but don't know if they are cheaper in Europe than Octopus

You can also order directly from ocp.de (you'll have to order by email, but can pay with paypal). You can get them even cheaper than if you get them from Octopus (for instance, I got 1L pigment black for 26.50 instead of the 39.20 Octopus charges).