Acceptable Chemical Grades For Alt?

"Generally"...where and when is it OK to use the lowest grades (technical)
as opposed to the highest grades (A.C.S ) when making emulsions and other
solutions in alt photography. Where can I save money and where to I need to
buy only the best. In a perfect world I'd use the purest of everything but
how much do the lower grades actually affect the outcome of a print?
Archival Standards? e.g. Silver Nitrate Technical is close to half the price
of A.C.S. grade is there a visible difference?

Chemical Grades

1. A.C.S. (American Chemical Society), Highest purity.
2. Reagent, almost or equal to A.C.S.
3. U.S.P. (U.S. Pharmacoepia) acceptable for drug use.
4. N.F. (National Formulary)
5. Lab, pure enough for "educational use".
6. Purified
7. Technical, for industrial use.

~m
Received on Tue Oct 18 18:35:42 2005