Digital BW, The Print

Epson 7600, QTR and Gui, UC inks (MK), Hahnemuhle Photorag, Win XP 
Pro, calibrated system.

The 8x10 proof prints I get on Photorag 308 match my monitor and look 
great and as desired. I can then make the same prints on a 24" roll 
of Photorag 188 (same printer, same everything) and get noticeably 
different results; namely, weaker contrast and weaker 3/4 tones. The 
188gsm prints look roughly 1/2 stop or more brighter in the shadows 
compared to 308gsm prints. As I said, everything is the same in 
making both prints. I've never understood otherwise, so I'm assuming 
I should be getting the same print results regardless of paper 
thickness, or am I mistaken? Is it possible that I have bad coating 
on my paper? I've recently started a fresh roll. 

Any help or ideas are appreciated.

Michael
www.mgordonphotography.com