From: Scott Wainer (smwbmp@starpower.net)
Date: 03/08/03-02:19:54 PM Z
Re: Kallitypes againHi everyone,
Thanks to all who replied; you've given me a lot to think about and try.
Sandy, sorry for the lack of information in my original post; it was late (for me) and I was tired.
The problem I seem to be having is that the shadow areas of the prints show splotchy areas of solarization/bronzing with an exposure of 2-3 minutes. The more exposure I give, the worse the problem gets and the lighter the shadow areas become. A curious aspect of the problem is that it only occurs where the negative is - the borders of the print (not covered by the negative) just get darker with more exposure. The less exposure I give, the darker the shadows get and the less highlight detail I have.
The negative I was trying to print was a partially sunlit, silver metal stairway decending in to darkness (80% of the print is pitch black). The enlarged lith negative shows a Dmin of 0.15 and a Dmax of 1.75 (resulting in a DR of 1.60). Kallitype should easily handle this type of negative; right?
What follows is my standard working procedure:
My darkroom and printing papers are kept at a constant 70F and 50-55% RH.
Sensitizer and coating -
30 drops of 20% ferric oxalate, 30 drops of 10% silver nitrate, and 4 drops of gum arabic per 8x10 negative coated over a 9x12 area on 11x15 paper taped by 2 corners to a sheet of glass and spread with a glass coating rod. 4 front to back passes (60-90 seconds?) leaves a very thin line of sensitizer left which I remove with a paper towel. I let the sensitized paper rest (2-3 minutes) while I clean and dry the coating rod and shot-glass. The paper is then dried with a hairdryer on the lowest setting approx. 12" from the paper surface (front and back) until the paper no longer feels cool to the touch.
Printing and processing -
I load the negative and paper into a printing frame and begin with an exposure of 6 minutes under a bank of 14 UV tubes (24" long) in an 24x26 area. I process by developing in sodium acetate (75g + 3g tartaric acid per 1000 ml) for 10 minutes followed by a 5 minute rinse, 10 minute gold-thiocanate toner, a 5 minute rinse, a 5 minute fix in 5% sodium thiosulfate, and a 20 minute wash. Prints are placed face up on drying screens and allowed to dry for 24 hours. I have found that with this procedure there is no need for a clearing bath (no stain/fogging in the border areas).
The silver nitrate was cloudy because I mixed it with filtered water instead of distilled; must have been some salts remaining in the filtered water. I made a new batch this morning using distilled and it is perfectly clear. I am going to buy a distiller since I use a lot in mixing chemistry and it is a pain buying it from the local store (my arms are about 2" longer now from carrying 20+ gallons a week - hehehe).
I tried Sandy's recommendations (even before he posted them) this morning. I tried using Arches Classic, Coventry Rag, and Fabriano Uno in addition to the Stonehenge (all of them sized and unsized - made no real difference). I also tried printing different negatives (same image but with negatives ranging from DR 1.20 - 1.80 though they are still lith negatives made from a 35mm negative). I tried doubling the gum arabic to 8 drops per sheet and eliminating it all together. Doubling and eliminating the gum arabic made no difference though changing papers and negatives did help quite a bit; but I am still getting splotchy areas of solarization in the shadows and printing times are extremely short - 2 to 3 minutes. The longer I expose the worse the problem gets and bronzing appears in areas not covered by the negative (borders).
Just for kicks I tried printing a paper inkjet negative (made on Epson photo quality paper) coated with mineral oil - what an improvement. There was only a small patch of shadows that was solarized and printing time increased to 8 minutes; though the shadow areas were quite light compared to previous prints. The inkjet negative, as best I can judge, has a DR of 1.50 (0.20 Dmin and 1.70 Dmax) but because of the mineral oil I can't be sure.
Bob, I would definately be inclined to try your idea of increasing the silver nitrate to 15% and cutting the ferric oxalate to 10% to reduce printing times but right now my printing times (with problems) are are only 2-3 minutes.
I got an off-list response on how to make potassium citrate and will try that as a developer. I would like to try sodium citrate, before buying in bulk, if someone could give me the proportions for sodium carbonate, citric acid, and water.
Thanks in advance,
Scott Wainer
smwbmp@starpower.net
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