Thank you, Ernst.
Yes, I have in fact been running my own window fade tests since I started printing, but of course if the paper is any good at all it can take several months for problems to show up. For what it is worth, I can tell you that the Hewlett Packard Vivera dye inks are amazingly good on HP Premium Plus paper - and pretty awful on any other paper Let's put it another way - is there any reason to suppose, given the experience of those here, that the Ilford Smooth Pearl will be any less archival than Epson's own Premium Luster?
John