Citric acid helps with clearing. Distilled water for initial clearing prevents bleaching. Image color is effected by humidity and drying time of the paper.
If your image is washing away in the clearing bath you have water issues. Get distilled water.
I always do double coats on my paper for VD. (OK insert giggles)
One thing I found was I could do 8 or so papers at a time and then by the time I coated the last I could usually get back to the first and do the second coat. I'd try to do processing all at one time so that I could use all 8 pages in one printing session. After 3 days or so the coated papers seem to be less active I guess you could put it. Consistancy from one print to another was easier to get to the best print this way. So with 8 pages I could usually guage 5 great prints a session and I would have 3 that usually were almost there.
I can get good d-max with a single coating if I use a glass rod. However, I tend to prefer the brush method, in which case I double coat for better d-max.
I find I can get perfectly consistent results as long as the following are always the same:
- time between the applications of the first and the second coating (I usually wait for half an hour)
- time between the application of the second coating and the exposure (I usually wait for an hour)
- concentration of the clearing bath
- clearing time
- concentration of the fixing bath
- fixing time
- toner concentration
- toning time
Do not wash the print after exposure in tap water! Tap water is often slightly basic, and basic environments convert the iron salts and form iron hydroxides, which have low solubility. This can make complete clearing impossible. That's why the first washing baths should be slightly acidic. Tap water is fine after the print has cleared completely.
Some acids are better than others. Citric acid is a strong chelating agent for iron and helps with its removal from the paper's fibers. Acetic acid isn't.
After exposure I wash the print in two 1% citric acid baths for three minutes each. No problem with clearing even with double coatings.
Don't use full strength fixer, and don't use rapid fixer. Just a 2-5% plain sodium thiosulfate solution will do. Anything stronger will bleach the highlights.
If you plan to tone in selenium, use a very high dilution. I dilute it 1+200, which gives me enough time to assess its progress and to stop the toning when the desired tone has been reached. If it's too concentrated, then not only will it partially bleach the image, but it will go to completion in no time, and completion means an ugly yellowish orange.
The print darkens considerably while drying. If it looks great wet, it's guaranteed to be too dark when dry. Try to aim for a slightly lighter than normal print.
When you mix the sensitizer, use a syringe to add the silver nitrate solution to the mix very slowly, just a couple of drops at a time, while stirring vigorously. Otherwise it will precipitate and will never dissolve again. Once mixed the sensitizer has good keeping properties. Mine is a little over a year old and is still going strong. I'll finish it off before it dies of old age.
Here's one of my latest vandyke prints. Double coating by brush, cleared in 1% citric acid for six minutes (two baths of three minutes each), fixed in 2% sodium thiosulfate for five minutes, toned in selenium 1+200 for three minutes, hypo-cleared in 2% sodium sulfite for five minutes. The paper is Fabriano Academia. 8x10" Kodak TXP developed in ABC.
Last edited by Vlad Soare; 03-15-2011 at 08:59 AM. Click to view previous post history.
Paper and sizing are very important. The suggestions above are good ones, but others also work. I have also found that double coating is needed for consistent results. You have to make new tests for every paper you use. It you use digital negatives, you may have to revise your curve for a new paper. Needless to say, consistent coating technique is important.