Bleaching small areas of a print -- what to use?greenspun.com : LUSENET : Large format photography : One Thread
I rarely bleach anything on a print but tried it yesterday on a small linear detail of medium density. (Seagull G, grade 2) I wanted to bleach it out to match the sky which was virtually pure white. No matter how strong I mixed my solution of potassium ferrocyanate it wouldn't quite bleach it out. Then, regardless of refixing and a long wash, there remains the slightest hint of yellow. I use this chemical because I have a big bottle of it and somebody said this was the way to go at a workshop I took once. What does this better and/or faster and/or without the stain? Thoughts I had were to try diluted drugstore iodine or maybe household bleach. As always, thanks in advance for your knowledge. Whatever chemical I use I promise not to spill it on Delicate Arch.
-- Kevin Crisp (KRCrisp@aol.com), April 08, 2001
I have used iodine a number of times for bleaching prints using Ilford MG FB. If you use it straight, it will definitely turn it paper base white. If you dilute it a whole lot (only 2 or 3 ml per liter), you can use it to slightly enhance the highlights. It works good, but it does take a little experimentation to figure out the exact dilution that works best for you.
-- Ken Burns (email@example.com), April 08, 2001.
Kevin, I tried bleaching some prints with the part a of sepia toner which is just really solution of potassium ferric. and they were very stained really bad. I recently tried bleaching some prints in nonstaining print bleach (the formula listed in Darkroom Cookbook)and wet they seemed clean so you may try that. I dont have the formula right here but maybe some one else will post it.-J
-- josh (firstname.lastname@example.org), April 08, 2001.
Kevin (and Josh), Bleaching and reducer shouldn't be misunderstood. Farmer reducer, the ferricyanide formula (not ferro...), and iodine will both wash out developed silver from paper and film. The same ferricyanide, when added to potassium bromide or similar, will actually transform metallic silver into silver halide again, making it possible redevelopment or toning processes. Farmer reducer isn't the best option for radical moves, but can do wonders if you don't try to speed things too much. Iodine works faster and deeper, and can do a clean job if followed by refixing. Play safe and don't change names! Good luck.
-- Cesar Barreto (email@example.com), April 08, 2001.
It seems to me that it is important to re-fix the print just prior to bleaching, otherwise you will have less bleaching action and more staining. If I find the print turning yellow from too much ferricyanide, I immediately apply some fix and it usually takes the color out. Also, you shouldn't leave the bleach on longer than a few seconds before washing it off. I have some tips on selective bleaching on my site at: http:/ /unblinkingeye.com/Articles/Printing/printing.html
Also, in "Lootens on Photographic Enlarging and Print Quality" (1946) there is a helpful paragraph on page 91: "If any stain remains in the print after washing and fixing, immerse it in a 5% Sodium bisulphite bath before the final wash. (Sodium sulphite or Potassium metabisulphite will also do.) This may remove all traces of discoloration. However, if yellow or red stains persist, wash the print thoroughly and let dry. Then, bleach it in the Chromium Intensifier and redevelop in ordinary developer. This last treatment will usually eliminate all reducing stains, although the print may become slightly warmer in tone."
-- Ed Buffaloe (firstname.lastname@example.org), April 09, 2001.
Try the BLIX bath from an E6 or C-41 kit. It washes out a lot easier and cleaner than ferricyanide. Last time I used ferricyanide bleach on a print, it took 12 hours to wash the stain out. If you want to make up a BLIX bath from raw chemicals it's Disodium ethylene-diamine-tetra-acetic acid (EDTA, disodium salt), and sodium thiosulphate (hypo). The proportions aren't that critical, about 50gm of each to a litre of water should do.
-- Pete Andrews (email@example.com), April 09, 2001.
I have had good results with Spot Off. It is an A/B solution bleach from the same folks that market Spot Tone. You can probably order it from Brandless/Kalt or any dealer that orders from them. Itís easy to work with, you can speed it up or slow it down by changing the ratio of A solution to B solution and if the directions are followed Iíve never had a problem with staining.
-- Joseph A. Dickerson (firstname.lastname@example.org), April 09, 2001.