Digital BW, The Print

Les: <... I didn't think to dark store identical copies. What I did do though 
 is cover portions of each print with opaque black cardboard. Lifting the 
cardboard should show any fading between the covered and open portions.>

Be careful with covering with black cardboard in window tests as the black 
may transfer heat to the covered portion of the print, and heat typically 
accelerates any changes. I'm doing a half-covered window test at the moment using 
foil as the cover exactly for this reason. You can read about it (it's ongoing) 
here:

http://www.dpandi.com/hj/windowtest

Covering only works if you have symmetrical images or uniform patches (I have 
the former on this test). I also have a reference print in the dark, and will 
probably go that route entirely with the next test.

Happy testing!

Harald
Harald Johnson
author, "Mastering Digital Printing, Second Edition"
DP&I.com ( http://www.dpandi.com )