making gum arabic solution, confused...

[timeUnit]

I followed the instructions on www.alternativephotography.com and mixed 30 g of gum arabic with 180 ml water. That solution looks and feels quite thin to me. Then I read Sam's instructions on unblinkingeye.com, and he uses 1 part gum to 2 parts water. Kerik uses 300 g gum to 1000 ml water.

Can I use the 30 g / 180 ml water solution, or is it just a waste of time? I'm planning on mixing it with pure pigments, chinacridone and vine black from Schmincke.

I'd like to print some tonight, but maybe I should wait until I get a thicker gum solution?

Thanks a million!
Henning

 

[CarlRadford]

Kerik is the man - I have followed his guidance with good results!

 

[Katharine Thayer]

Well, you could try it and see what happens, but I suspect you'd be happier with a thicker gum mixture. I read through that article, and that's not the only questionable or factually inaccurate statement in it (for example, the idea that one could mix a 30% solution of potassium dichromate --- good luck!) I find it interesting that the person chosen to write this "how-to" article about gum printing doesn't seem to be a gum printer. His work in the gallery at the site is all cyanotypes, and I can't find gum prints by him anywhere else.

Yes, stick with Sam or Kerik.

The traditional standard for the gum arabic used for gum printing has always been 14 Baume, which is a measure of specific gravity rather than viscosity or actual proportions. Til now I've always used liquid gum that has been mixed to the 14 Baume standard, but I'll be starting soon to mix my own. It seems there's some latitude in what works, given that people use anywhere from 1:2 to 1:3 or more; gum:water, but I haven't heard of any gum printers using 1:6 before. I think you should be able to just add more gum to your thin solution rather than starting over, but I hope someone who is more experienced with mixing gum will jump in here.
kt

 

[Jim Noel]

I would simply add another 30gm of gum.

 

[timeUnit]

Done!

Thanks!

 

[timeUnit]

I've e-mailed alternativephotography.com with a suggestion of a better recipe for the gum arabic solution.

 

[z-man]

gum arabica

Well, you could try it and see what happens, but I suspect you'd be happier with a thicker gum mixture. I read through that article, and that's not the only questionable or factually inaccurate statement in it (for example, the idea that one could mix a 30% solution of potassium dichromate --- good luck!) I find it interesting that the person chosen to write this "how-to" article about gum printing doesn't seem to be a gum printer. His work in the gallery at the site is all cyanotypes, and I can't find gum prints by him anywhere else.

Yes, stick with Sam or Kerik.

The traditional standard for the gum arabic used for gum printing has always been 14 Baume, which is a measure of specific gravity rather than viscosity or actual proportions. Til now I've always used liquid gum that has been mixed to the 14 Baume standard, but I'll be starting soon to mix my own. It seems there's some latitude in what works, given that people use anywhere from 1:2 to 1:3 or more; gum:water, but I haven't heard of any gum printers using 1:6 before. I think you should be able to just add more gum to your thin solution rather than starting over, but I hope someone who is more experienced with mixing gum will jump in here.
kt

wise to rely on premixed comercial solutions since they are selling a garantee that you will get the same thing every time you buy

gum arabica is a loose term since there are several different species of accacia trees and then there are other trees that also produce gums-the commercial 14baume is usually a blend--its like makeing wine-the same tree will give a different gum if the weather changes

the gum sold for the offset printing trade is also very consistent

gum was most often sold to the fabric printing industry so it was formulated for that process

somalia is the largest source of 'gum arabica' and the situation there has thrown the cottage industry of gathering the gum out of balance

egypt is the best place to buy from-the brokers there have been in the trade for a thousand yrs

vaya con dios