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  1. #111

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    I really like longevity, and for film Polyester seems to be the best,
    wikipedia mentions that some film has it as a backing,
    but it seems like most use volatile acetate base,
    are there any brands that still use polystyrene base for 135 or 120?
    Or is the only option now to make my own polyester film with emulsions?
    Last edited by streondj; 10-08-2012 at 11:54 PM. Click to view previous post history.

  2. #112
    holmburgers's Avatar
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    The triacetate that's used for film is very stable in its own right, but my understanding is that yes, polyester is the best base for longevity and dimensional stability.

    Not sure about polystyrene...

    Kodak large format films are all on polyester, and I've seen some 135 film on polyester as well (Rollei I think...)
    If you are the big tree, we are the small axe

  3. #113

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    Ya, triacetate is good for 50-100 years or so, but then it's prone to turning back into vinegar.
    polyester however is rated for 1000+ years when it comes to archival purposes.
    http://comminfo.rutgers.edu/~lesk/sp...ife-expect.pdf
    i believe in reincarnation, so would love to have previous photos available.
    Though of course also good for grandchildren and the like.
    polyester films can outlive fiberbased prints .

    polystyrene was actually a typo, though apparently it's used as a base
    for kodalith ortho films http://albumen.conservation-us.org/l...lhoun1959.html
    it is however mildly biodegradable, by certain bacteria.
    btw, perhaps could melt clear plastic bags (polyethylene) and roll them into film.
    I've melted plastic bags and made toy boats out of them.
    though not sure the film would be hydrophilic.

    Thanks for that info about the Rollei polyester base-films, i'll get some :-).
    Last edited by streondj; 10-15-2012 at 02:44 AM. Click to view previous post history.

  4. #114
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    Be careful with polyester though, it pipes light! I agree though, an amazing plastic really. UltraStable made a white polyester base for the transfer of their carbon prints; owing credence to the thought that it might outlive fiber based papers.

    There are polyester films available, and some chemical etching techniques show promise for making it hydrophillic.
    If you are the big tree, we are the small axe

  5. #115

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    Desperately looking for Dura Lar for wet media

    Hi to you all, I've been trying to find a supplier for Grafix Dura Lar for wet media on Continental Europe.. I really have contacted quite a lot of firms, including Fotoimpex in Berlin. Most of the time a negative reaction and even worse no reaction at all. Does anyone out there in the US have better contacts with suppliers as to find out why this apparent backwardness in Europe exists. At the moment it seems there is no other option than to order in the US or in the UK. Thanks a lot for your answers. I still don't think I am the only one searching for it. I am happily brewing my Lightfarm Emulsions but I would like to "spoil" more than just glass plates and anyway I did read that a new the lightfarm Tutorial on Roll film is scheduled for mid July, I'd like to have my materials ready by then. I also asked in German and Dutch, to no avail. Thanks a lot for your help. Henk

  6. #116
    kb3lms's Avatar
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    Henk,

    I don't know if you can order through Amazon, but they list Duralar Wet Media in sheets and rolls. It's not a photographic product, per se. Have you tried art stores? That is where I bought mine. If they don't recognize the Graphix brand, talk to them about wet media mylar films. It seems that critical thing you are looking for is 4 mil (.004 inch) thickness. (I don't know if or what the metric equivalent is.) If you can find a 4 mil wet media film I believe they are all really the same, or very similar, material.

    -- jason
    All this has happened before, and all this will happen again.

  7. #117

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    Hi Jason, thank you. I can order Dura Lar in the UK but it seems a bit funny not to be able to order Dura Lar on Continental Europe.Could anybody who knows Mirko of Fotoimpex perhaps prod him a bit to start and stock Dura Lar for wet media. I contacted Fotoimpex but no reaction. I have a bit of emulsion in the fridge, I am going to use it on an old piece of 120 film I still have, but that will not last for ever. Thanks, Henk.

  8. #118
    kb3lms's Avatar
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    Little Help?

    Finally, I have obtained a (complete) copy of Glafkides "Photographic Chemistry." One of the things I was interested in was a subbing recipe for acetate. At this point most of us are using wet-media PET films for actual coatings but I have been interested in subbing acetate one, because I never got it to work and two, because I have a small pile of acetate. Note, this is cellulose diacetate, not triacetate, according to the manufacturer website.

    I am aware that many here say that Glafkide's book has errors and omissions. OK, so knowing that, a subbing recipe given in Glafkides book for acetate is not terribly different from many I have read in patents. Here it is:

    • Gelatin 1g
      Acetic Acid 2g
      Water 4ml
      Nitrocellulose 1g
      Acetone 60ml
      Methanol 32ml


    According to the book, page 468, the gelatin, acetic acid and water are allowed to soak for a few hours and then melted in a water bath. The nitrocellulose is then added. So far, so good. Here is the problem: On adding the acetone, a white insoluble rubbery substance forms immediately. I assume the white substance has something to do with the gelatin. Any ideas what this white substance is and how to avoid having it form?

    I've had this happen most of the time when making acetate subbing formulas, which is one of the reasons I gave up on it. The acetone used is sold as 100% Acetone fingernail polish remover and the ingredients are given as acetone and denatonium benzoate, which is a bitter substance used at very low concentration.

    Thanks for any help,
    Jason
    All this has happened before, and all this will happen again.

  9. #119
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    Jason;

    In the first place, that appears to be a formula for subbing cellulose nitrate base not cellulose acetate. Also, the concentration of the Acetic Acid is not specified. I assume it is glacial AA. Heating too long or too hot will denature the gelatin.

    Acetone should be free of ALL contaminants. It should be chemically 100% Acetone and not have any denaturants.

    If you can get a better formula and better acetone, you will be better off. That formula is close to the ones I have seen though. Gelatin, AA, some plastic and a solvent. I'll take a look at my formulas here, but no promises. Everything I have worked with was presubbed.

    PE

  10. #120
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    Hi PE,

    Sorry, yes it is glacial Acetic Acid. What does denaturing the gelatin mean?

    Pre-subbed is definitely the way to go. The wet-media Grafix PET is great stuff, no frilling and no stripping but a bit on the pricey side.

    Not too long ago I obtained a 400 foot roll of clear 35mm triacetate film leader. It was manufactured by Kodak and is also pre-subbed. I suppose it is really just uncoated film base. Maybe it didn't meet their quality specs for use in a coated product so they sold it as leader.

    I will still probably get some pure Acetone. I do wonder about the denaturant in the acetone I have, though.

    Glafkides gives a simpler formula on page 467 for nitrate subbing consisting of:

    Gelatin 1.2g
    Acetic Acid (glacial) 2g
    Water 5ml
    Methanol 92ml

    Glafkides doesn't give a specific formula for subbing triacetate.

    Anyway, thanks and Happy New Year!

    -- Jason
    All this has happened before, and all this will happen again.



 

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