RE: VDB Color
Frances, > Recently I experimented with a citric acid first bath and noticed a loss of Dmax. > In the final print? There is always a significant lightening of tones in the first citric acid clearing baths that should be regained through toning and dry down. I have to make test prints and dry them to see how the print looks dry. If it's too light then an adjustment to exposure is made. Unfortunately this means that you also have to use a potentially expensive toner like a gold solution for test prints. But that expense is offset by the low expense of the process where the paper becomes the most expensive component. Often I'll just process test strips of several negs at the same time. Of course most if not all of this is negated if you are using digital negatives and you have your digi-negs well calibrated. > Perhaps I mixed too much citric acid into the solution. Christopher James mentions a pinch. Did I equate a pinch with a spoon (which is what I would use with the Ware cyanotype)? I need to test and compare citric acid at the beginning and end but why would it matter when the citric acid bath was applied? EDTA is applied at the end of end of processing palladium and ziatype and citric acid is the first step in new cyanotype (Ware). Would EDTA be a more effective iron solvent? > Which EDTA? But yes an acidic solution of EDTA might be used by citric is so much cheaper and very little is need. > How long would yellowing highlights take to show up? My earliest prints using this workflow are from Spring of 2008. > I can't answer that. > The paper I have is relatively lightweight (compared to Aquarelle); a kozu unryu. > By light weight I take it that the implication is that it would be easier to clear residual iron compounds. BTW this is the last post I can make for a few days as I hit the road tomorrow and return Tuesday. Perhaps our other VDB mavens will chime in and offer their sage advice. Don
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