Use glyoxal. Read the archive.
> i do not do any of these things and have been getting gum prints good enough for
> display in national institutions for over twenty years.
> When they are published people come to see me from around the world. Judy does
> not believe me.
Terry, what makes you think I don't believe you? I believe you
implicitly. It's just that I lack your talent(s).
> tooth." If you use Fabriano 5 or Bockingford you will not need to size for the
> first coat. Dichromated Gloy as an undercoat obviates the use of any size at
> all. Judy believes I am telling fibs.
Terry, I never for a minute suspected you of fibbing. (See above.) But I
must add, speaking of paper, that if the Bockingford is too coarse for
your taste, you can use burlap. Don't know the Fabriano 5. What's the
texture quotient? However, I recently make a print on Saunders Waterford
HP, which I foolishly hadn't used before. Excellent.
And speaking of paper, someone along in here said I use Rives BFK. Not
true. I myself don't use Rives BFK because I find the texture too coarse
for what I'm trying to do. But I start students with it; it's practically
no-fail.
> You will get far better results if you measure out the solutions with an old
> spoon. I use the same proportions.
If you're using a viscid gum, which I do, too much clings to the spoon.
Besides a 5 ml spoon of gum and a 5 ml spoon of sensitizer makes a
minimum of 10 mls mixed. Often much more than I want of a single color.
As for the dropper bottles, there's no washing at all. I have bottles for
various gums (including one with skull & crossbones for Gloy) and a
couple for sensitizers, tho obviously one of each would be fine. You drop
out your drops or squirt your squirts & screw the dropper with cover
attached back onto the bottle. What's to wash? (We buy the brown 2 oz
dropper bottles by the gross for school from lab suppliers.)
> . I never weigh or measure the pigment. I mix the pigment with the gum on a
> white plate until I have the strength I need. That is what painters do.
Some painters.
> why do photographers need to be different.
If you're in a dry climate, such as a steam-heated NYC apartment, or the
Arizona desert, the moisture will evaporate too quickly from your pigment
if it's spread out in a thin layer on a plate. We don't all live in dewy
England.
>
> Appreciable differences in behaviour of the colour usually result from the
> amount of pigment that is needed for a given saturation. This results from the
Terry, as your copy editor, I request a rephrase of that first sentence.
I think I agree with it but can't tell for sure.
> reflectivity of the different colours. Because the make up of colours can vary,
That's for starters. Each pigment has its own chemistry and each
manufacturer uses a different version of the "same" pigment. For
instance,I tried burnt sienna, by Rowney, Smith, Winsor Newton, Schmincke,
Holbein, & a few others I forget. All were different. And although I found
Rowney had "the best" burnt sienna, they had the worst ultramarine (never
would clear). Etc. Etc. Etc.
And don't dismiss gouache out of hand. It's excellent, superb, non-pareil
for one-coat gum. I also understand, BTW, that the legendary Steven
Livick uses gouache, among other colors.
Judy