To make the pH more acidic, you should use either Citric Acid, Sulfuric Acid, or Acetic Acid. These should be very dilute. Do not use Nitric Acid or Hydrochloric Acid. If you wish to use Ascorbic Acid, that adds a twist to the situation as it is an antioxidant and a developing agent. It can be used, but has some side effects.
Thanks, PE. I will check into that.
Last night I made a coating that has turned out to be very fogged. The PET was washed very well in fresh water, so I don't think that was the problem. It was a small coating, about 10 or 12 ml, as I wanted to try photo-flo (5 drops) again and glyoxal plus erythritol . Now I forgot to dilute the glyoxal and used 1 ml full strength. Anything to point to there as a foggant? I'm suspecting the stock strength glyoxal since I have used photo-flo and erythritol before, although not together, without problems.
The good news is that while this coating is unusable for photographs, its adhesion properties are very good.
All this has happened before, and all this will happen again.
At that level, you should have very hard coatings. I have never tried glyoxal at that level.
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.
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...)
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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.
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.
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.