Either I missed something (Panix is picky) or this began as a private
exchange, spread to list. Either way, Sandy, would you fill us/me in?
You're making your own tissue for carbon printing?
I'm particularly intrigued because I have found pigments for gum
bichromate printing exactly as idiosyncratic as you say - only different.
That is, dispersions, pigments, you describe didn't work, and vice versa.
And a supposed pigment (eg ultramarine) that's difficult in one brand
(Rowney, which is generally good) is fine & dandy in another (in this case
Daniel Smith, which has a new line of water color & gouache, somewhat
cheaper than other brands. Of the two I tried, ultramarine was terrific,
lunar black didn't clear at all).
I have also found that pigments in dispersion as a rule DON'T work with
gum printing, at least not for me. I tried several brand-named Createx
(maybe from the Hartford CT co. you mention, though address isn't on
label) and they didn't clear. I had also bought some from Guerra paint &
pigment here in NYC & they didn't clear either. Then I went to Kremer
pigment company, which has a store here in Soho but based in Germany (I
believe), runs mail-order world wide, bought several blacks. Their
"furnace" black, a lamp black (suggested by Stephen Livick in Canada by
way of Jeff in Sweden -- how's that for global village!) was available in
two forms: in dispersion, which the lady said was glyacol (is that right?)
and as a dry pigment. Naturally the in-dispersion is preferable, saves
grinding & handling powder. But it DID NOT CLEAR! The powder cleared fine
and makes a beautiful, fine grained, rich black.
My chem-prof friend at school, when taxed with this inexplicable
behavior, said something about how the glyacol holds the pigment (will
have to write it down next time), but it does seem that none of the
in-dispersion pigments have worked well (ie, cleared) for gum bichromate,
for me at least, in my protocol. I haven't worked with the Furnace black
very much, but so far it looks very good.
Incidentally I made the formula from Scopick (glycerine, sugar, foto flow,
gum arabic, etc.) supposedly for "plasticizing" powdered pigment, and
can't help wondering if he ever really tried it, or simply copied it from
Mayer (which he cited as source). Whatever, it made every pigment I tried
it with stain badly. I looked it up in Mayer, where it seemed to be for
making pigment more easily handleable for painting -- doubt Mayer knew or
cared about our uses. In any event, if I haven't mentioned take Scopick
with .1 g salt, I've been too kind.)
> >
> I once used watercolor pigments but don't any longer. For color
> work the cyan and magentas lack the transparency of pure pigments, and
When you say you used watercolor *pigments*, I take it you mean watercolor
*paint* from tubes? (Pigments may all be the same, no?)
> monochrome I have had good success with the Grumbacher Finest series
> of watercolor, specfifically with Ivory Black, Lamp Black, Raw Sienna,
> and one or two others. The great advantage of watercolor pigments is
> that they disperse wonderfully.
Someone told me that Grumbacher wc was discontinued, but that may have
been only their Academy or student series.
>
> All of my current tissue is made with so-called pure pigments from
> the Color Craft Company of Hartford, CT. These pigments are available in
> 4 and 8 oz bottles and are much more economical than the small watercolor
> tubes. I have also obtained numerous pigment samples from companes like
> Dupont, Heubach, Cib-Geigy, etc.
The dry pigment, tho more nuisance, is also economical. I did incidentally
at the same time buy a "pigment" called bitumen, thinking to walk in the
footsteps of Niepce. Well, if his didn't work better than mine, it's
amazing we got photography.... Anyway, I'd add Kremer to that list of
pigment companies. I'd also suggest that if you find a pigment you're
specially fond of, buy a lifetime supply -- mines run out (as Venetian
red did about 20 yrs ago) & manufacture changes.....
> As for dispersions, nothing special. I use 35g of sugar per 1000ml of
> gelatin solution, and 10-15ml of glycerine. I first grind everything
> up very carefully with a pestle and mortar, then mix in a blender at
About how long? What's "careful"? You grind wet or dry?
> medium speed for 2-3 minutes. This kicks up a lot of air bubbles and
> you must wait for 2-3 hours to coat, but gives wonderful dispesion.
> A friend of mine tried the blender and swore that it did not work, that
> the bubbles would never go away. But it works fine for me.
S/he he obviously had different manufacturer of blender -- a big variable!
Sandy, if you've elaborated on this already, can you give me the date?
Otherwise, when you say "dispersions," do you mean your gelatine-pigment
mix for coating tissue? You don't mention amount of pigment, I suppose
that varies. I have, BTW, tried sugar in gum emulsion, as recommended by
Puyo (he says "a little" which isn't quite as inspiring as 35g/1000 ml).
Sometimes it helps & sometimes it seems not to, or even to be worse --
but then every variable changes all the other variables, which is about
the only generalization I can make from some 3 months of testing (then I
went to the Betty Ford clinic and kicked the habit, at least pro tem,
until the next binge....... :-)
Judy