Re: Contrasting agents

[Richard Sullivan <richsul@earthlink.net>]

There is a paper by me, low tech and one by Howard Efner PhD. (Chemist), 
high tech on Na2.

Perhaps the one by Dr. Efner will answer some of your questions.

On out site:

http://www.bostick-sullivan.com/Technical_papers/NA2/NA2%20papers.htm

--Dick sullivan


At 10:04 AM 5/15/2002 +0200, you wrote:
>Hello Folks,
>
>Is a contrasting agent in Pt/Pd processes (or even cyano) just working
>as an oxidizer ? Meaning that it reduces the density evenly on the
>print, and as the concentration is low, the reduction is low too. This
>gives burned highlights. Isn't it more a reducer than a contrasting
>agent ?
>I would expect a contrasting agent to boost the high densities.
>
>Does one of you have Pt/Pd DlogE curves and experiments to share about
>it ?
>
>Thnak you,
>
>Cheers,
>
>Philippe