Re: Seeking Information on 2 problems with Gum process
I just performed a simple test: I bleached a very dark cyanotype in ammonia. It lost density and turned lavender. Washed it and put it in straight vinegar. The color came back to the original cyan, but no density returned. Time will tell, but I'm thinking that the density is gone for good. At least I hope it is, because I just sold several prints that I doctored in this fashion.... On Wed, Apr 30, 2008 at 8:53 AM, sam wang <stwang@bellsouth.net> wrote: > Keith, > > Would you know how permanent this method leaves the image? Would the > reduction continue, or could it be arrested by reapplying acid to it? The > acid would make it slightly a different blue in some cases by the way. > > It's a very useful way to control cyanotype density if indeed it is > permanent. > > Sam Wang > > > > > On Apr 30, 2008, at 9:29 AM, Keith Gerling wrote: > > > > As my well-water is somewhat alkaline, the cyanotype layer bleaches > > out slightly during the subsequent gum stages. My approach is to > > overprint the cyano layer to the point where it is much too dark, and > > then to bleach it back to where I want it when the gum is finished. I > > use dilute ammonia. > > > > > > > > On Wed, Apr 30, 2008 at 5:50 AM, cadunn <cadunn@vt2000.com> wrote: > > > > > Henry wrote: > > > but I found it much better to dilute > > > > > > > > > > the coating solution with anything up to six or seven times its own > volume > > > > with water. You can hardly see it as you coat it, but the blue is > there OK > > > > and you can give it full exposure. Dilute solutions seem to need > rather > > > > > > > less > > > > > > > exposure than full-strength ones. > > > > > > > > > > > > > > > > > lol, Henry -- your msg. came JUST after I had coated the paper and was > > > planning on a much reduced exposure time, which is all at this point in > my > > > learning curve that I knew to do -- > > > > > > So, next iteration of cyanotype stage variation belongs to you! > > > > > > Thanks > > > > > > > > > >
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