Digital BW, The Print

Has anyone out there who has been using Hahnemuhle PR for a long time 
had any yellowing problems? I am about to spend a lot of time and money 
on printing a portfolio with this paper and my concern is the fact the 
HPR has optical brighteners.

I did give Entrada Natural White paper that does not contain OB's but I 
did not like the paper as much as HPR.

-Jeff