I was using the same card from the same supplier. I was using the same printer profiles and settings, the same software. The only change that happened was that I had to replace the magenta cartridge. It is possible the magenta is what is lacking in the problem cards.
I had ordered a new pack of pigment ink cartridges but it wouldn't be delivered in time for my last batch of cards so instead I went to Tesco and picked up a lower capacity version and had to use that instead. I am wondering just how long that pack has been on the shelves. There cannot be much call in a superstore like that for pigment ink cartridges, most people use dye based ink printers. Can ink go-off? I don't know,
There is now another problem. I have now received the ink I had ordered from Amazon. But I cannot change the ink in the printer because for some unknown reason the carriage will not centre to allow me to take out the ink cart.
So frustrating, more problems all the time.