A high powered microscope has been used to scan various papers showing how they handle ink. Pictorico papers are available by phone or may be ordered over the net. Like Epson's Glossy Film Pictorico Hi-Gloss Film has a notch in the upper right hand corner of the printable side. One package of Pictorico paper that I received though had the notch on the wrong side. The best way to check if you are printing on the correct side is to be sure that you are using the glossy side, not the satin finish side.
Pigments are much more resistant to fading than are dyes.
This claim remains to be independently verified. I'm a fine-arts photographer, not a scientist, but I have conducted some accelerated fade tests and the results are that on Epson Photo Paper Generations inks actually fade faster than Epson's own inks. The answer is, uneventful if you're using one of the less glossy papers such as Epson Photo Paper. I was pleasantly surprised to discover that the colour shift is relatively minor. In fact colour accuracy is quite good and the real difference seems to one of contrast and saturation.