So much information. After the intital post I was out of touch for a few days. This post has grown with so much with vaulable information. My original question was realted to a slight increase in contrast. Jorge is correct. My intent is to start printing pt/pd. My current method is printing on Azo. The past few years I have been exposing about 1.5 stops extra...i.e. my Zone IV is exposed as a Zone V. With an average 4" exposure I double for reciprocity and add another 50 %. Then I develop by inspection and push the highlights as far as possible. So in general I can produce an print on Azo grade 3 with some amount of burning on the highlights. My concern is that some negatives may reqiure a tad extra density for pt/pd printing. Overall my negatives have an increased amount of density so I should be okay. Once I start printing I will know for sure yet I wanted to do some intial research. I have known for years there were claims that Selenium toning adds stability to a negative. Thanks again to all who posted.

-Bruce