Digital BW, The Print

Hello,

I've been printing with Hahnemuhle Photorag 308 for the past 
three months and have accumulated quite a pile of test prints 
that are scattered about.

The prints on top of the heap or pinned to the wall have turned 
yellow within a couple months of being printed.

The prints behind glass or under shrink wrap appear to be 
holding up. Still, I'm concerned about the rapid aging of this 
otherwise great paper.

Has anyone else noticed this?

Regards,

Jeff