I have made a simple test: I just printed a neutral grey file (L* = 50, a = 0, b = 0) on a small 10 x15 cm Epson Premium Glossy Photo Paper using absolute colorimetric intent. After letting the print dry for a few hours, I made the following two readings with my i1Pro2 in spot mode:
1) Reading on a spot located 10mm from the beginning of the print
L = 50.27, a = 2.63, b = -3.13
2) Reading on a spot located 10mm before the end of the print
L = 50.66, a = 2.60, b = -1.59
I have repeated the same test 5 times with similar results. The difference is not very big but it is there and can be seen with the naked eye too.
What do you think?