Liam Lawless (lawless@vignette.freeserve.co.uk)
Wed, 10 Mar 1999 00:18:27 +0000
Hi Adam,
I'd mainly like to reiterate a point Dave made about paper - in my
experience you must use a hot-pressed paper for argyrotype, otherwise you
will see the image wash off the paper during the washing stage (you'll see
it disappear as a brown cloud over the clean margins). I don't have much
experience with the method, but I have used Arches Aquarelle HP and Fabriano
Artistico HP successfully. Mike says that varying the amount of Tween (a
wetting agent) enables it to be used with a wider range of papers, but this
I have not found necessary as I have only a few papers in stock. (Maybe it
would enable rough/cold-pressed papers to be used, but somehow I doubt it.)
Everything you need to know is on Mike Ware's site, the address of which I
think someone else gave. For 100ml of sensitiser you need 7g sulphamic
acid, 7g silver oxide, 22g ferric amm. citrate (green), 0.2ml Tween 20, plus
distilled water. For processing, only hypo (2% solution) and gold for
toning, if desired.
Instead of the 7g of silver oxide, Mike says 8.4g silver carbonate can be
used instead, but Ag2O is extremely easy to make by adding a solution of
2.5g sod. hydroxide in water (volume immaterial) to a solution of 10.3
silver nitrate. The precipitated silver oxide is supposed to be filtered
and washed, but I do it the lazy way, swilling the precipitate around in
fresh distilled and carefully pouring off 2 or 3 times. Works just fine...
but who knows what my prints would be like if I did it properly!!!
An easy, inexpensive process, well worth trying, BUT I have two batches on
the shelf, made in August and November '98. The November batch has put down
a small amount of black precipitate (silver?) which began to appear several
weeks after making, while the August batch has rather more precipitate at
the bottom of the bottle, with what appears to be white mould growing on it.
Last time I tried (maybe 6 weeks ago), both still worked.
I think the sensitiser is claimed to have a shelf life of a year, so it may
be that I've gone wrong somewhere, but I suspect that the mould problem is
to do with the ferric ammonium citrate. When I use it in blue toners or in
cyanotype sensitisers, I usually add a drop of thymol (1-2ml of a 2%
solution in isopropyl alcohol for every 20g of f.a.c.), and this prevents
mould entirely. (I have had f.a.c. solutions go like they came out of
someone's nose, until I started using a fungicide.) Salicylic acid should
do the same thing, but probably more would have to be used. I didn't use it
in the argyrotype because Mike doesn't specify it, and I was worried about
upsetting the chemistry.
Liam
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