Ok here's what I did.
In a small mortar I put 5 drops of gum 14% Baume (.29 gms) Made here from
powder.
I then added .12 gms of Sinopia Phthalo Blue pigment. This is somewhere
between a 1/4 and 1/2 a teaspoonful! Probably closer to the 1/2. As he said
to do, I mixed it with the pestle until the gum just barely took up the
pigment. It was a stiff glossy mass. More like a shiny thick film in the
bottom of the mortar. I then added 3.0 gms of concentrated ammonium
dichromate solution. @ 2.5 mls.
Basically it is all counterintuitive to a gum printer. He says to put in
some pigment and add just a few drops of gum until all the pigment is taken
up. In my case a big pile of pigment and a few drops of gum. You then you
add 4 to 6 times (or more) the amount of dichromate solution.
I then coated the paper. A little streaky but very very dark coating,
darker than I recall from my der gummidruck days of 20 years ago. (Why
anyone would want a gum print that looked just like a cyanotype is beyond
me but it is the pigment I found first. I can't find my badger blender either!
I exposed it and developed it. I am used to my substrate method where the
expsoure is short and the development is short. But I left this in the tray
for about an hour and then used a stream from the sink hose to bring it up
quite nicely. I couldn't resist so I did a very light underwater noodling
with the brush too.
Ok it is not a gold medal print, but all indications are that the old boy
was right. His methodology is so far out in left field that if he was
totally nuts, nothing would come up, but it did, so this tells me that
there is some truth here.
I tried this before many years ago but I may have had too much gum in the
mix. You have to make it real stiff.
I haven't yet tried the other half of his system this go round. That is
developing between blotters between two pieces of glass. The glass blotter
stack is then set edgwise in a tray of water for a day or so. When I tried
it before, I got a mess, but then I didn't do the gum-pig ratio right
either. Maybe I'll get to trying the blotter thingdo soon as well.
I am intrigued.
--Dick Sullivan
Bostick & Sullivan
PO Box 16639, Santa Fe
NM 87506
505-474-0890 FAX 505-474-2857
<http://www.bostick-sullivan.com>http://www.bostick-sullivan.com