From: Neil Miller (neil@miller.gioserve.com)
Date: 01/16/03-04:10:27 AM Z
Hello.
I have recently started making vandyke brownprints and am having a problem with a silvery deposit over part of the image, not unlike that often seen on old b&w photos. It occurs about 70% of the time and is most apparent on darker areas of the print and on papers I have double-coated (which usually exhibit a silvery or white line where the top coat has not overlapped the bottom coat).
It appears to be a very fine layer of sparkling crystal deposits that is not only on the surface of the paper, but trapped within the upper fibres. It is more pronounced on papers with a rough surface, but is still very apparent of BFK and Saunders Waterford. The only paper that does not have a trace of the problem is Daler 96gsm smooth white cartridge from an artists sketchpad, but this is too thin and wrinkle-prone for me to process succesfully.
I make three solutions up, each with 35ml of distilled water. (A) has 10g of green ferric ammonium citrate, (B) has 1.5g tartaric acid and (C) has 4g silver nitrate. All are well stirred until dissolved. (A) is added to (B) and well stirred then (C) is added drop by drop while stirring. The solution is left to age, filtered, then applied with a hake brush or a foam applicator. The paper is left to dry in a warm, dark room overnight or is force-dried with a fan heater. All work takes place in a windowless room illuminated with a 100watt bulb, positioned well away from the work area. I have used a 40watt bulb and a red safe light, but can see no difference and no evidence of fogging, so have gone back to the 100watt bulb.
I expose for between 4 and 15 minutes (depending on the neg) under a bank of UV lights, rinse under running tapwater for 5 mins, fix in a bath of 25g plain hypo crystals in 100cc of tapwater for 2 mins then wash for 20 mins. I used to use 50g of hypo crystals to a litre of water and fix for 5 mins, but this seriously bleached the prints to an unacceptable degree. The print turns a gorgeous colour when it hits the fix, but then fades away, hence the lower concentration (2.5%?).
I am tempted to think that the fix is not removing all the residual silver, but I have heard of people who omit the fix altogether and they have not reported this problem. I do change the fix frequently. If anyone has any ideas, I would be very grateful to read them.
Many thanks,
Neil.
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