Re: concentration of 14 baume gum arabic
I never use premixed gum. In fact, I mix the powder oftentimes right before use.
Be sure to put a preservative in it or it will sour very quickly if you mix a batch that will stand around more than a few days! I use drops of thymol, 1 drop of 100% thymol in methylated alcohol per 5 oz. of gum.
An approximation of 14 baume is 300g powder in a liter container, adding water to make a liter. But gum varies in moisture so anywhere between 280 and 320 is the range. That said, it doesn't much matter if you are 14 baume; Demachy used to use 18-20, then 16-18 became norm and now it is 14 so there is an acceptable range.
Christina Z. Anderson
----- Original Message ----- From: "Dirk-Jan Treffers" <firstname.lastname@example.org>
Sent: Wednesday, September 03, 2008 4:50 AM
Subject: concentration of 14 baume gum arabic
Dear list members, does anyone know what concentration of (powdered) gum arabic in water most likely will come close to 14 baume gum arabic that you buy in art supply stores? I've searched on the internet, but could not find a direct answer. Maybe anyone here can help me out? I'm getting a bit sick of paying rediculous prices for very small bottles, and have 1 kg of powdered gum. When I mix it in a 1:1 ratio, the gum looks far more dark that the regular solution, and I'm afraid that will taint my final gumprint... Anyone have any ideas on this matter? thanks in advance! cheers, Dirk-Jan