Since I generally have ammonium dichromate on hand, I have used that with
apparent success in many formulas calling for potassium dichromate -- as
for instance in reducing or "harmonizing" bleaches, or tray cleaners, as
well as in certain circumstances in emulsions. For the latter such small
amounts are used I doubt the difference in cost would be a factor. K di is
still available about $14/lb, and no hazard shipping charge, am di is 20
something + hazard shipping & harder to find). I use about half the
amount, on assumption that saturated solution is about twice as strong. As
I say, it seems to work....... but you don't mention it as contrast
agent possibility here. Any comment?
>
> Another method I have tried with success is to add a drop of dilute
> potasium dichromate 101326.553@compuserve.com (to result in the above percentages) to the coating
> mixture. This gives excelent results on sharp textures like bricks.
> However, the dichromate does end up in the enhancer changing the
> characteristic of the enhancer as each print is processed.
>
> Jeff
>
But while we're on the subject, I note that though many VDB /kallitype
formulas also make such claims, I've found addition of either K or am
dichromate in most cases seriously deteriorates the emulsion....
Judy
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