Hi Mario, Already responded to your earlier email so that's in your inbox. Coming back to the Photo Black issue though, I would say the next sensible step would be to try ruling out the Photo black by investing in a single OEM PGI-29 PBK cartridge, installing it and then doing a purge to ensure that the lines are clear of any of the compatible ink. Then allow a rest for half an hour before testing things out. Chances are the purge won't completely clear the lines so a few test prints with breaks between... and if other Pro-1 users recommend it, a second purge to be sure..
It's a serious waste of ink and it may not work out as hoped but if it does prove an issue with the compatible ink then there's something for me to investigate further.
I should note, we're not expecting it to be an issue, as this is not something we're seeing with other Pro-1 users at all, and the inks we have are over 18 months in circulation now. But I'm not going to assume either...
Your call but just thought I'd see if anyone else was thinking along the same lines...