[pure-silver] Re: FW: Sepia toning & Potassium Bromide & Ira B Current
----- Original Message ----- From: "titrisol" <titrisol@xxxxxxxxx> 
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Tuesday, November 20, 2007 4:29 AM
Subject: [pure-silver] Re: FW: Sepia toning & Potassium Bromide & Ira B Current 



Developer also plays an effect in the final tones.
Ethol LPD produced colder chocolate when used more concentrate, have not tried it with Dektol. 


C.Breukel@xxxxxxx wrote: FYI
Its evident that the structure of the original image affects toning considerably. Since the structure is affected by the developer its not surprizing that this should be so. In general, the finer the original silver grains the more effective a toner will be. Also, the orginal image color is mostly decided by the grain structure, the finer the grain the yellower the image color. so, warm tone papers tend to tone more effectively in most toners. For the most part the yellowish (or brownish) image in warm tone papers will tend to produce more yellow browns from sepia toners. The bleach and redevelop toners, also called indirect toners, tend to produce more yellow colors on any paper than direct toners like polysulfide (like Kodak Brown Toner) or Hypo-Alum types, so they are preferred for use with cold tone papers which may not tone to a desirable brown using direct toners. OTOH, they may produce too yellow a color when used with warm tone paper. The old rule of thumb was that adding bromide to a developer would result in finer grained and therefore warmer toned images which would also tone warmer. Current's experiments, as reported in his patent, indicate that if very large amounts of bromide is added the reverse happens, at least in respect to the image resulting when the paper is toned. Modern paper emulsions seem to be quite different from those of the time the patent was issued so they may not behave the same way. Nonetheless, its an interesting thing to know about and I am glad Cor tried it and reported to us. Its also evident that various developing agents and the activity of the developer also affect the original image color and probably also the color of the toned image. Also, I should point out for clearities sake that not all toners produce brown images. We are discussing mainly those which convert part or all of the image silver to silver sulfide. Other toners, for instance the various gold toners, also are affected by the color of the original image. Gold, used by itself, for instance, produces a blue image. On cold tone paper the effect is mainly to intensify the image slightly but the blue color becomes more evident on warm tone papers, the warmer the original tone the bluer the toned image. Selenium toner behaves in much the same way except the resulting image color is purplish brown. 


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Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx 
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