Faster salt prints?!

Discussion in 'Alternative Processes' started by Donald Qualls, Apr 19, 2006.

  1. Donald Qualls

    Donald Qualls Member

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    I've been reading up on salted paper prints, and have just gotten the chemicals in to try a few ($30 for 10 grams of silver nitrate -- whew!). In my reading, I note that the general use is sodium chloride (canning or kosher salt, or technical grade) or ammonium chloride, or a mix of the two. I don't, however, see any mention of people using bromide salts for the salting step, and I wonder why. If I understand this side of things correctly, silver bromide is both more sensitive, and sensitive to longer wavelengths than silver chloride, which would give a much faster print, especially if exposed under light that isn't filtered to remove visible wavelengths.

    I got a pound of potassium bromide with my recent chemical order -- at the time, I think mostly because I'd forgotten that developers that call for this chemical mostly want tenths of a gram per liter, though I'd also be able to use it in rehalogenating bleach for redevelopment processes. However, a liter of 2% mixed salt solution, equal parts sodium chloride and potassium bromide, wouldn't need a huge amount of the more costly salt and ought to produce significantly faster salted paper.

    Has anyone tried this? Are there contrast problems, issues with printing-out failures, or other reasons not to use a bromide salt for salting the paper before sensitizing with silver nitrate solution? On a similar note, has anyone tried developing-out a latent image from much shorter exposures on salted paper?
     
  2. donbga

    donbga Member

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    Please tell us you are pulling our leg. You can purchase an ounce of AgN03 for $10 plus shipping from e-bay suppliers.

    There is no need to spend this much money for silver nitrate.
     
  3. Photo Engineer

    Photo Engineer Subscriber

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    Donald;

    That price is kinda high. Where did you get it? The usual price at that quantity or lower is about $1 / gram. The price quoted by Dongba is a little low based on my sources and quality does count.

    As far as I know, the use of bromide in salt prints was not common. I can look into it, but my biggest expert is out of town for several weeks.

    PE
     
  4. donbga

    donbga Member

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    I expected PE to mention the quality of silver nitrate and I can tell you that I've been using $10/oz silver nitrate for years with alt process with no problems, however Art Craft is selling it for about a buck a gram. Much less for larger qtys. Unfortunately prices have risen over the past months.

    I hope this isn't the Hunt brothers all over again.
     
  5. David A. Goldfarb

    David A. Goldfarb Moderator Staff Member

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    I was just going to order a pound from Artcraft at $169/lb, if anyone wants to split it with me. I'm not looking to make a big group order, but if someone wants, say 50-200 g worth, I'd be happy to sell that much at my cost plus whatever the shipping/packaging is, since a pound is more than I can use in the immediate future.
     
  6. Photo Engineer

    Photo Engineer Subscriber

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    Well, I did say "quality does count" in my post.

    I would add that it is probably less important when making salt prints than when making silver halide crystals by precipitation.

    At EK we had regular reviews of silver nitrate for quality, and sometimes had to reject large batches of silver nitrate for impurities that were usually traces of heavy metals or iron.

    PE
     
  7. Donald Qualls

    Donald Qualls Member

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    Okay, I checked my receipts, and in fact I did pay $10 for the 10 grams, from Artcraft. I could have gotten an ounce for $30 at the other place but didnt' quite have that much money and decided 10 g would do for now, just conflated the amounts and prices when posting above. These crystals were absolutely colorless and transparent in the bag, and dissolved in 80 ml of water to make 12.5% solution in just about one minute of gentle swirling (and yes, I have the solution in a dark brown container, an old yeast jar as it happens).

    So far, I've done some quick and dirty VDB prints, using just the silver nitrate and the ferric ammonium citrate solution I have for cyanotypes, and they worked decently; more experimentation is in order, and I'm sure there are good reasons the canon formulae have half a dozen additional ingredients.

    But I'll know what's up with the salt prints in a few days at most; I've got the KBr on hand and can get kosher or canning salt at the market over the weekend (I'd just use table salt, but the box says it's got dextrose, sodium bicarbonate, a trace of potassium iodide, and sodium silicoaluminate -- no idea if those would cause problems or not, but kosher salt doesn't have any of that stuff, I'm told). I'll try salting a few sheets with straight NaCl, a few with straight KBr, and a few with an equal mix, sensitize them with the silver nitrate, expose them all with the same negative under the same light for the same time, and see what I get.
     
  8. CRhymer

    CRhymer Subscriber

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    Hi Donald,

    Kosher salt does not have iodides, but may have other additives (contrary to popular belief). It probably has calcium silicate if domestic or other anti-caking agents if imported, but it will probably be just fine for your purposes. If you are measuring the salt by volume, remember that the particle size is larger than table salt - not a problem with a scale.

    Cheers,
    Clarence
     
  9. Marc Leest

    Marc Leest Member

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    Donald, any results ?
    I was wondering too what salts could be used for salted print:

    Sodium chloride
    Ammonium chloride

    Potassiumbromide ?
    Ammoniumbromide ?
    PotassiumIodide ?

    many thanks, Marc
     
  10. juan

    juan Subscriber

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    A photography professor at the University of North Florida has been making nothing but salt prints for the past 25-years. He recommends ammonium chloride. I've seeen his prints, and they are very good. Far, far better than my feeble attempts regardless of which salt I use.
    juan
     
  11. nworth

    nworth Subscriber

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    About a year ago, I paid $40 for 100g of reagent grade silver nitrate. Now, the same supplier (Hi-Valley Chemical) is charging $53.82. Not a huge increase, despite the near doubling of the commodity price for silver. Quantity makes a difference here. Small quantities (like 10g) always have a higher price - mostly due to the cost of packaging and documentation.

    As to the original question: I've seen potassium bromide recommended as the salt for salt prints. (I think it was in "Keepers of the Light", but I'm not sure.). From what I remember, the speed (as a printing-out paper) may not be that much different, but the image tone will be a bit different. This may be an interesting control, since you could mix the chloride and bromide salts.
     
  12. Jim Noel

    Jim Noel Member

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    I see no reason the bromide or the mix of chloride and bromide won't work. I hope you will be posting some results soon.
     
  13. juan

    juan Subscriber

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    I've used KBr as the salt. It works in that it produces an image. I have not experimented enough to tell if I like it. It is faster than sodium chloride and produces a more black than brown image.
    juan