Philip
You write:
>
>
> Pete, I'd hesitate about recommending 1% sulphuric acid on
> a) health and safety grounds
> b) it performed only marginally better
> c) acids are bad news for paper
>
a) I can see no health and safety grounds for not using 1% sulphuric acid.
This must be one of the safest chemicals we handle in alt-photo!
b) When Pete F showed me his samples I would say it performed dramatically
better,
c) I would expect sulphuric acid to wash out without problems - and if not
it could readily be neutralised and washed out. Given the slightly alkaline
pH of my wash water this would probably occur in any case.
Peter Marshall
On Fixing Shadows, Dragonfire and elsewhere:
http://faraday.clas.virginia.edu/~ds8s/
Family Pictures & Gay Pride: http://www.dragonfire.net/~gallery/