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#1
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Add Kodak Brown to KRST?
I've googled this group and found numerous posts saying that KRST at 1:20
doesn't provide adequate archival protection because it won't tone the highlights. Would adding 1:200 of Kodak Brown Toner to the 1:20 of KRST help without changing the overall tone? Thanks, Mike |
#2
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Add Kodak Brown to KRST?
Hi Mike,
I think so. Research done at the Image Permanence Institute in Rochester and published in the Abbey Newsletter (available on line) indicated that at one time KRST was more effective at providing archival results than as currently sold. The research found that the earlier KRST had a small amount of sulfurated postash (aka liver of sulfur, potassium trisulfide) "contaminating" the product. The active ingredient in Kodak Brown Toner is potassium sulfide. Both potassium sulfide and potassium trisulfide have toning properties. The latter is also said to be able to remove silver complexes. So, using the Brown Toner may not get you all of the benefits of using the sulfurated potash, but it should get you at least some of them. I do know that some contributors to the group experimented with various ratios of Brown Toner. I cannot remember if all of the results were published, but I think that I recall that 1:200 was yielded satisfactory results for those who tried it. Francis A. Miniter Mike wrote: I've googled this group and found numerous posts saying that KRST at 1:20 doesn't provide adequate archival protection because it won't tone the highlights. Would adding 1:200 of Kodak Brown Toner to the 1:20 of KRST help without changing the overall tone? Thanks, Mike |
#3
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Add Kodak Brown to KRST?
Mike wrote:
I've googled this group and found numerous posts saying that KRST at 1:20 doesn't provide adequate archival protection because it won't tone the highlights. Would adding 1:200 of Kodak Brown Toner to the 1:20 of KRST help without changing the overall tone? Thanks, Mike Not sure about the nitty and the gritty of toning permanance issues. But the standard thing to do is to tone with more than one toner. Here is an article on it. Remember that there is an order to the toning... http://unblinkingeye.com/Articles/Double/double.html |
#4
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Add Kodak Brown to KRST?
"Mike" wrote
I've googled this group and found numerous posts saying that KRST at 1:20 doesn't provide adequate archival protection because it won't tone the highlights. I think the silver in the highlight areas accepts selenium as readily as the silver in the shadow areas. If they are truly less archivaly protected then some other mechanism must be at work. I think it may be a purely precieved lack of tone rather than an actual non-reaction twixt the selenium and highlight silver. In other words, I'm not a subscriber to the "split tone" school from the chemistry's view point. Dan |
#5
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Add Kodak Brown to KRST?
Dan Quinn wrote: "Mike" wrote I've googled this group and found numerous posts saying that KRST at 1:20 doesn't provide adequate archival protection because it won't tone the highlights. I think the silver in the highlight areas accepts selenium as readily as the silver in the shadow areas. If they are truly less archivaly protected then some other mechanism must be at work. I think it may be a purely precieved lack of tone rather than an actual non-reaction twixt the selenium and highlight silver. In other words, I'm not a subscriber to the "split tone" school from the chemistry's view point. Dan Sorry, Dan, but Mike is right on this. Selenium affects shadows before highlights. First, I want to clarify a couple items from my previous post. In my previous post in this thread I had referred to research done at the Image Permanence Institute at the Rochester Institute of Technology. The work was done by Dr. Douglas Nishimura, a research scientist at the IPI. In fact, I had occasion to inquire of him in and for a while he posted to this news group some superb summaries of his research into image permanence. This was back in year 2000. I had also mentioned research done by participants in this group. One such was undertaken by Lloyd Erlick who summarized his results in a post started September 14, 2000, and entitled: "T-8 Brown Toner and Selenium Toner in Combination". Dr. Nishimura, Richard Knoppow and I were contributors to that discussion. I also at some point posted a chart of tonal changes resulting from selenium toning in various papers after development in several different developers. As to the affect of KRST on shadows and highlights, it definitely affects shadows first. I have myself done extensive testing (noted above) to determine which papers exhibit what tonal change with selenium, and in the course of those tests, I observed, consistently, that tonal changes occur first in shadows, and only many minutes later in the highlights. I also have regularly engaged in split toning (selenium/brown toner), toning first in selenium and second in brown toner. The result is that black tones remain black and highlights go brown, while the affect on mid tones depends on the amount of time in selenium. This is not just my observation, however. I refer you to Dr. Tim Rudman's most recent book "The Master Photographer's Toning Book: The Definitive Guide" (Argentum, 2003), where on page 42 he states: "Prints that have been fully selenium toned robustly resist attacks by most image destroying chemicals. However, not all the commonly recommended archival toning regimes are valid. This is a reflection on the advice given rather than on the toner, because selenium toner initially affects the shadow areas before the mid tones and highlights and short toning times in highly diluted toner do not allow toning to proceed far enough for all the image-silver to be converted. The highlights and possibly the mid tones may therefore be unprotected. " Dr. Rudman also sites the IPI research. See page 158 of his book. On page 159, he further explains that the shadow values have the finest grains and that is why selenium tones them first. The problem is that the color shift accompanying full selenium toning is often unacceptable. This is why many people try to selenium tone to a point before the tonal shift occurs. And this is why confusion arose because KRST used to have a modicum of sulfurated potash in it. The potash provided protection in the highlights that the selenium was not providing. But with the "purification" of KRST, this subtle protective affect was lost. Thus, we have to deal now with the problem of how to achieve protection without an annoying tonal shift. Mike is on the right track. On further reflection, it may be better to use Kodak Polytoner rather than Kodak Brown Toner, to get some potassium trisulfide into the mix. Francis A. Miniter |
#6
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Add Kodak Brown to KRST?
"Mike" wrote
I've googled this group and found numerous posts saying that KRST at 1:20 doesn't provide adequate archival protection because it won't tone the highlights. Would adding 1:200 of Kodak Brown Toner to the 1:20 of KRST help without changing the overall tone? Kodak Polytoner was a mixture of brown and selenium toner, it is no longer made. You can make your own mix. I don't know the ratios -- I bought a few quarts of PT before stocks disappeared and still have some on hand. Francis Mitner wrote: ... at one time KRST was more effective at providing archival results than as currently sold. The research found that the earlier KRST had a small amount of sulfurated potash (aka liver of sulfur, potassium trisulfide) as a contaminant ... To ask the obvious: why not add a pinch of "Liver of Sulfur" to KRST? Available at most arts & crafts stores -- around $15-30/lb, $8/4oz. UPS doesn't like to ship the stuff. -- Nicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. psst.. want to buy an f-stop timer? nolindan.com/da/fstop/ |
#7
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Add Kodak Brown to KRST?
On Sun, 25 Apr 2004 16:59:35 GMT, "Nicholas O.
Lindan" wrote: .... To ask the obvious: why not add a pinch of "Liver of Sulfur" to KRST? Available at most arts & crafts stores -- around $15-30/lb, $8/4oz. UPS doesn't like to ship the stuff. .... apr2604 from Lloyd Erlick, I think this could literally be done, and I'd guess it is being done by many darkroom workers. If you want a weight of potassium polysulfide (liver of sulfur) to use, I'd say pinch your thumb and index finger in a container of table salt and weigh that. Weigh out that amount of sulfide for each liter of selenium toner working solution. In fact, this may be a bit too much. The problem I had was the smell of the sulfide. It gave off hydrogen sulfide (rotten egg gas). I searched for an amount of sulfide I could put into my selenium toner and not smell it, and also not get a 'brown toner' toning result. I found a very small amount of solid potassium polysulfide in water could really stink the place up. But in view of the fact that only a very small concentration of sulfide in the toner will (apparently) provide archival protection qualities, I think the literally-a-pinch amount should do the trick. Frankly, I'd be inclined to use a pinch per gallon. regards, --le |
#8
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Add Kodak Brown to KRST?
Lloyd Erlick wrote
"Nicholas O. Lindan" wrote: To ask the obvious: why not add a pinch of "Liver of Sulfur" to KRST? Available at most arts & crafts stores -- around $15-30/lb, $8/4oz. UPS doesn't like to ship the stuff. apr2604 from Lloyd Erlick, I think this could literally be done, and I'd guess it is being done by many darkroom workers. I searched for an amount of sulfide I could put into my selenium toner... IIRC, The Abbey Newsletter to which Mr. Miniter refers in an earlier post this thread, reports that sodium sulfide at a 1:9,999 dilution confers very good archival qualities to microfilm. IIRC, microfilm is the principle subject of that article and if I'm not mistaken, a priority item at the RIT's IPI reaserch facility. BTW, Mr. Miniter provided an interesting link. I thought your work with brown and selenium and in combination very interesting. Also, the IPI director if I'm not mistaken, provided valuable information with regard to gold, platinum and sulfur preservation. He did not discuss selenium. Dan |
#9
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Add Kodak Brown to KRST?
"Francis A. Miniter" wrote in message ...
Hi Mike, I think so. Research done at the Image Permanence Institute in Rochester and published in the Abbey Newsletter (available on line) indicated that at one time KRST was more effective at providing archival results than as currently sold. The research found that the earlier KRST had a small amount of sulfurated postash (aka liver of sulfur, potassium trisulfide) "contaminating" the product. The active ingredient in Kodak Brown Toner is potassium sulfide. Both potassium sulfide and potassium trisulfide have toning properties. The latter is also said to be able to remove silver complexes. So, using the Brown Toner may not get you all of the benefits of using the sulfurated potash, but it should get you at least some of them. I do know that some contributors to the group experimented with various ratios of Brown Toner. I cannot remember if all of the results were published, but I think that I recall that 1:200 was yielded satisfactory results for those who tried it. Francis A. Miniter Mike wrote: I've googled this group and found numerous posts saying that KRST at 1:20 doesn't provide adequate archival protection because it won't tone the highlights. Would adding 1:200 of Kodak Brown Toner to the 1:20 of KRST help without changing the overall tone? Thanks, Mike AFAIK, the research at IPI never determined what the change in KRST was. Do you know of later research on this? There was speculation that there was some sulfide or polysulfide as an impurity in one of the ingredients. Kodak claims that the formula and method of manufacture have not changed. Full toning with any sulfide or polysulfide toner, or with Selenium or Gold toners, provides full image protection. The problem with KRST is when it is used as long recommended, i.e., at a 1:20 dilution. According to personal communication with Dr. Nishimura, KRST will provide full protection when used at a dilution of no greater than 1:9 and for not less than 3 minutes at 68F. Polysulfide toner made so that the concentrate has high order polysulfides, will tone all densities uniformly so will provide full protection even when only partial toning is done. Kodak Brown toner, at the recommended dilution works fine as does T-8. Agfa Viradon should work as well. Kodak Polytoner, and the older version of Viradon, were combinations of Polysulfide and Selenium. These toners provide full protection but were less desirable for microfilm because they affect the crystaline structure of the silver to a greater extent than either polysulfide alone or KRST. This is of no consequence for pictorial negatives or prints. I have never seen any formal testing of KRST with added sulfide or polysulfide. Kodak had a formula for making a combination toner from KRST and KBT, I've posted it to this group a couple of times. Ryuji Suzuki tells me he has tried it and found that it caused strong orange stains on prints. Polytoner was discontinued some time ago but Kodak maintains the secrecy of the formula. Gold toner provides very good image protection but does cause some shift in image color for printing paper. The shift is toward blue so may be desirable for some papers. The problem with Gold toner is that it is expensive even at the relativly low concentration of Gold used in protective toners. It appears that stabilizers, like Agfa Sistan, are effective in preventing oxidation of the image silver. Sistan, in particular, has not been fully tested. A test of a similar (but not identical) Fuji products, called Ag-Guard, suggests that the effectiveness is not as great as toning but is nonetheless significant. These products do not affect density, image color, or crystaline structure. Highly diluted Polysulfide toners can cause serious staining. Polysulfide has the peculiar property of toning faster as it becomes exhausted or more diluted. For this reason the use of highly diluted toner of this type is not recommended. In fact, the use of a 10% solution of Sodium Sulfite is suggested as a sort of stop bath following toning in Kodak Brown Toner or Agfa Viradon to prevent staining from the toner remaining active in the wash bath. Washing after toning should be quite vigorous even when this bath is used. I am skeptical of toning in a simple solution of sodium sulfide since it does not affect silver directly. In fact, sodium sulfide is used as a test of unfixed halide. It tones the halide very effectively causing a stain if fixing is not complete. It does not significantly affect metallic silver. Richard Knoppow Los Angeles, CA, USA |
#10
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Add Kodak Brown to KRST?
Hi Richard,
I just re-read the article: Nishimura et al "Stabiality of Black-and-White Photographic Images, with Special Reference to Microfilm", Abbey Newsletter July 1988 vol 12 No. 5 You are right. They do not specify which sulfide they thought was the problem. They wrote: "It is our strong feeling that the changes in formulation that suddenly rendered dilute selenium toner ineffective relate to the sulfiding action of minor constituents. Although the formula for Kodak Rapid Selenium Toner is proprietary, it is known to contain both sodium sulfite and hypo (sodium thiosulfate), both of which may be contaminated with small amounts of highly active sulfiding agents. Apparently insignificant manufacturing changes may have caused this active agent to be no longer present; it would still form silver selenide and achieve a toning action (in the sense of color change), but would no longer protect against peroxide. In any case, the surprising ineffectiveness of Kodak Rapid Selenium Toner, together with many other signs of the potency of sulfiding agents, pointed the way to a much different analysis of image stability and how to achieve practical protection against red spots." Later on, in discussing sulfiding treatments is where they took up Kodak Brown Toner. They wrote: "There is great promise for sulfiding treatments as a way of protecting microfilm against oxidative attack. Once we had determined that the sulfiding ingredients were in fact responsible for most of the protection imparted by dilute selenium and gold toners, we began to explore the effectiveness of various compounds which might form a layer of silver sulfide at the surface of developed silver grains. This work is still under way, but already at least one simple, extremely effective approach has been identified: the use of polysulfides, as found (for example) in the commercial product "Kodak Brown Toner." This product gives complete protection in our severe hydrogen peroxide test (2000 ppm), even when used in quite dilute solution (for example, 1 part toner to 200 parts water). "It is characteristic of the sulfiding approach that only a small amount of the sulfiding agent is needed. For example, sodium sulfide solutions of 0.1 grams per liter (about 1/100th of a percent) are completely effective. However, for reasons of diminished odor, toxicity of the bulk substance, and shelf life of the solution, the polysulfides are preferable in practice to straight sodium sulfide. We have shown that Kodak Brown Toner does its work of protecting the image silver without significant change of density or image hue. The method of treatment is simple: processed microfilm of any age can be immersed in the solution for a few seconds (shorter immersion times require slightly higher concentrations than longer times), then washed and dried. Conventional processing equipment can be readily used for post-treating, with throughput rates comparable to normal processing." Francis A. Miniter Richard Knoppow wrote: "Francis A. Miniter" wrote in message ... Hi Mike, I think so. Research done at the Image Permanence Institute in Rochester and published in the Abbey Newsletter (available on line) indicated that at one time KRST was more effective at providing archival results than as currently sold. The research found that the earlier KRST had a small amount of sulfurated postash (aka liver of sulfur, potassium trisulfide) "contaminating" the product. The active ingredient in Kodak Brown Toner is potassium sulfide. Both potassium sulfide and potassium trisulfide have toning properties. The latter is also said to be able to remove silver complexes. So, using the Brown Toner may not get you all of the benefits of using the sulfurated potash, but it should get you at least some of them. I do know that some contributors to the group experimented with various ratios of Brown Toner. I cannot remember if all of the results were published, but I think that I recall that 1:200 was yielded satisfactory results for those who tried it. Francis A. Miniter Mike wrote: I've googled this group and found numerous posts saying that KRST at 1:20 doesn't provide adequate archival protection because it won't tone the highlights. Would adding 1:200 of Kodak Brown Toner to the 1:20 of KRST help without changing the overall tone? Thanks, Mike AFAIK, the research at IPI never determined what the change in KRST was. Do you know of later research on this? There was speculation that there was some sulfide or polysulfide as an impurity in one of the ingredients. Kodak claims that the formula and method of manufacture have not changed. Full toning with any sulfide or polysulfide toner, or with Selenium or Gold toners, provides full image protection. The problem with KRST is when it is used as long recommended, i.e., at a 1:20 dilution. According to personal communication with Dr. Nishimura, KRST will provide full protection when used at a dilution of no greater than 1:9 and for not less than 3 minutes at 68F. Polysulfide toner made so that the concentrate has high order polysulfides, will tone all densities uniformly so will provide full protection even when only partial toning is done. Kodak Brown toner, at the recommended dilution works fine as does T-8. Agfa Viradon should work as well. Kodak Polytoner, and the older version of Viradon, were combinations of Polysulfide and Selenium. These toners provide full protection but were less desirable for microfilm because they affect the crystaline structure of the silver to a greater extent than either polysulfide alone or KRST. This is of no consequence for pictorial negatives or prints. I have never seen any formal testing of KRST with added sulfide or polysulfide. Kodak had a formula for making a combination toner from KRST and KBT, I've posted it to this group a couple of times. Ryuji Suzuki tells me he has tried it and found that it caused strong orange stains on prints. Polytoner was discontinued some time ago but Kodak maintains the secrecy of the formula. Gold toner provides very good image protection but does cause some shift in image color for printing paper. The shift is toward blue so may be desirable for some papers. The problem with Gold toner is that it is expensive even at the relativly low concentration of Gold used in protective toners. It appears that stabilizers, like Agfa Sistan, are effective in preventing oxidation of the image silver. Sistan, in particular, has not been fully tested. A test of a similar (but not identical) Fuji products, called Ag-Guard, suggests that the effectiveness is not as great as toning but is nonetheless significant. These products do not affect density, image color, or crystaline structure. Highly diluted Polysulfide toners can cause serious staining. Polysulfide has the peculiar property of toning faster as it becomes exhausted or more diluted. For this reason the use of highly diluted toner of this type is not recommended. In fact, the use of a 10% solution of Sodium Sulfite is suggested as a sort of stop bath following toning in Kodak Brown Toner or Agfa Viradon to prevent staining from the toner remaining active in the wash bath. Washing after toning should be quite vigorous even when this bath is used. I am skeptical of toning in a simple solution of sodium sulfide since it does not affect silver directly. In fact, sodium sulfide is used as a test of unfixed halide. It tones the halide very effectively causing a stain if fixing is not complete. It does not significantly affect metallic silver. Richard Knoppow Los Angeles, CA, USA |
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