Re: Gallic acid; Was:
another easy way to optain (pure) tannin/tallic acid: Simple buy a small jar at your local 'make your own wine at home' store. In my hometown Utrecht (Holland), I bought two jars of 20 grams each for 3-4 euro per jar.... 40 grams will make 4 liters of toning liquid, enough to last for (well...this all depends on how often you make cyantypes, AND tone them....) but for me, on the occasional toning i do with cyanotype, this will give me plenty of toner for a couple of years. Best not to make one batch, but simply prepare a 1% solution (so, 10 grams per liter). If stored in brown jars, and hidden away from sunlight, I see no reason why these powders can't last a couple of years on the shelf... after about 2 minutes of toning in the tannic acid, rinse in water, and then finalize the toning in a 1% sodiumcarbonate solution (again for 2 mins or so), again rinse in water, hang to dry... et voila! (but i guess this information isn't new to you guys, as the experts... just wanted to make my small contribution to the list!) kind regards, Dirk-Jan 2008/8/23 Jack Fulton <jefulton1@comcast.net>: > Native American basket makers have used oak galls boiled in water to make a > dye. They also have used a rusty pan (iron) to make it darker. The galls > have been powdered rather than cut up in pieces or used whole. Another way > is to use a combination of ether and alcohol (watch out for the ether) but I > don't know the ratio but assume it to be 50/50. That extracts the gallic > acid from teh galls which is then very miscible with water. I'd refrain from > using iron if you boil the galls for the iron can make speckles of stains > like we have seen in cyanotypes from using water from the tap that includes > small particles of iron coming from the pipes in the house. > Chris is right in using walnut husks for they contain the acid as well. > Here is some info garnered from an on-line encyclopedia: > Common tannin, or tannic acid, C14I-i1509.2H20, occurs to the extent of 50% > in gall-nuts, and also in tea, sumac and in other plants . It may be > obtained by extracting powdered gall-nuts with a mixture of ether and > alcohol, whereupon the tannin is taken up in the lower layer, which on > separation and evaporation yields the acid . When pure the acid forms a > colourless, amorphous mass, very soluble in water, less so in alcohol, and > practically insoluble in ether . > Jack F > > > On Aug 23, 2008, at 10:34 AM, Christina Z. Anderson wrote: > > Hi Linda, > I did not use oak per se but I used walnut husks and boiled a cup or two of > them in a bunch of water for a while and used the water as the toning bath. > I got my walnut husks from a basket maker. The method is very loose because > in basket lore, a basket maker would just have an old barrel filled with > rain water and toss the walnuts in that and then use it for dyeing. It is > very archival. I have NOT done this with cyanotype but with gelatin silver > prints so I cannot guarantee it will directly apply to your situation. > > I have toned with gallic, though, that I bought from Artcraftchemicals.com > > Hope this helps, > Chris > __________________ > > Christina Z. Anderson > http://christinaZanderson.com/ > __________________ > > ----- Original Message ----- > From: Linda Stinchfield > To: alt-photo-process-l@usask.ca > Sent: Saturday, August 23, 2008 11:12 AM > Subject: Re:Gallic acid; Was: > Speaking of toning cyanotypes, I recently gave a cyanotype workshop for my > book arts group, and we did some toning with tannic acid, using tea. I > mentioned that gallic acid was also sometimes used but I'd never tried it. > Well, someone from the group just gave me two bags (!) of oak galls. Does > anyone know how to extract gallic acid from oak galls-- or even if it's > possible? > TIA, > Linda > > > > On Aug 22, 2008, at 5:08 PM, Robert W. Schramm wrote: > > > BTW cyanotype can be toned to achieve colors other that blue and white. > > Good luck with your work and welcome to alternative process printing. > > Bob Schramm > > >
|