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This topic comprises 2 pages: 1 2
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Topic: How often should you rewind prints in storage?
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Leo Enticknap
Film God
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Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000
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posted 01-12-2004 01:40 AM
First off, standard archival practice is to store elements wound base out, because it minimises stress to the emulsion caused by base scratches and of accidental damage when handled. As William points out, the bottom line for long term film storage is: as cold and as dry as you can manage. If these are acetate prints either vented containers (which can be created simply by drilling a few holes in the side of the can) or molecular sieves (small bags of a chemical compound which sit in the can and absorb the acetic acid fumes from decomposition) are a good idea. If you go for the hole-drilling option make sure your storage area is well-ventilated.
If you do rewind regularly you want to wind the element tight enough to prevent layers of film from abrading against each other and potentially causing scratches when handled, wound or lifted; but not so hard that the emulsion of one layer is being pressed into the base underneath it.
Relating to William's Richard III anecdote, I've often heard it said that nitrate manufactured between the very beginning and around WWI is some of the most durable film stock ever made, possibly because good quality, low acidity wood pulp was used to produce the cellulose and the manual, flat-casting methods before industrial scale base manufacture with band-casting plant kicked in evaporated a greater proportion of nitric acid than was later the case. I've also heard it said that 1940s nitrate some of the most volatile and the first to decompose because cheap, highly acidic pulp was used as a wartime austerity measure and the demand for base was at its highest for any point during the nitrate period.
I've certainly seen evidence to back that up: a year or so ago we got a 1912 print of a local newsreel covering a football match. It had spent most of its life at room temperature and humidity. It was in very good condition, float test negative, had barely shrunk at all and the lab we sent it to for preservation duping was able to make the polyester negative by straightforward continuous contact printing. A few months later I was asked to look at two elements from 1943: they had already gone sticky and were beyond saving - a bonfire in the car park job.
This book, though mainly about colour fading, contains chapter and verse on film preservation environments.
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Jeffry L. Johnson
Jedi Master Film Handler
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Posts: 809
From: Cleveland, Ohio, USA
Registered: Apr 2000
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posted 01-12-2004 07:31 PM
A quote from AMIA-L:
quote: SMPTE Recommended Practice (RP)-131-2001 which replaces the 1994 version, which has recently been trial published in the SMPTE Journal, as follows:
4.3.2 Storage enclosures:
"The recommendations in this clause are taken from ANSI/PIMA IT9.2 and 4.1 of ANSI/PIMA IT9.11. Refer to those documents for additional information. Motion-picture film is wound on reels or cores and stored in roll form. Rolls should be wound emulsion in and title in, but not under extreme tension. Rolls mounted on cores, particularly those longer than 500 ft, should be stored flat (horizontal) unless the core itself is carried on a horizontal spindle to prevent the lower part of the film from supporting the load of the core. If such rolls are on spools which have flanges, a spindle is not required since the flanges support the weight of the roll."
Storage and Handling of Processed Film quote: Extended Storage Time - 10 Years or More
Color dyes are more prone to change than silver images when kept for extended periods of time. The following minimum guidelines are suggested for keeping films for 10 years or more:
• Adequately wash the film to remove residual chemicals such as hypo. See ANSI PH 4.8-1985 for recommended levels and a testing method for residual hypo.
• Some color films designed for processes other than ECN-2 and ECP-2D may require stabilization during processing (e.g., some reversal films using process VNF-1). Always follow recommended process specifications and formulas.
• All film should be as clean as possible, and should be cleaned professionally. If you use a liquid cleaner, provide adequate ventilation. Adhere to local municipal codes in using and disposing solvents.
• Keep film out of an atmosphere containing chemical fumes. See "Effects of Contaminants" above.
• Do not store processed film above the recommended 21°C (70°F), 20 to 50% RH for acetate or polyester.
• Wind films emulsion-in and store flat in untaped cans under the above conditions.
Additional information can be obtained from ISO 2803 or ANSI PH1 43-1985, "Practice for storage of processed safety photographic film."
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Leo Enticknap
Film God
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Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000
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posted 01-13-2004 01:43 AM
quote: NO NO NO NO NO NO NO!!
That's the worst thing to do; it will lead to the film develping a curl! An archive search will bring up threads with more detail on this
Not if stored in reasonably constant temperature and humidity it won't, and if there is even the slightest bit of shrinkage the stress on the emulsion caused by 'stretching' it outwards will cause a lot more damage than any base curl will. Remember that, as a general rule, when film shrinks, it's the base which shrinks, as either nitric or acetic acid parts company from the solid. As the base shrinks relative to the gelatine and emulsion layers it applies stress to the latter.
There might be an argument for storing polyester elements emulsion out given that it doesn't shrink in the same way that nitrate or acetate does, but I don't know of any archive which does this as a matter of policy.
And I've certainly found that release prints (of all bases) on a platter tend to be much happier emulsion out; but they're doing a different job from elements which are being kept for long-term preservation. Assuming it's spent most of its life being stored at room temperature and humidity (or worse), any '50s or '60s acetate element is likely to be significantly shrunk and give problems in projection. That problem is likely to be worse if it's spent half a century wound emulsion out. I suppose that by then reversing it you might help to 'stretch' the base a little, in the same way as if you take an element that's spent several decades wound on a 2" core or tiny spool hub and then put it on a 3" core for a few weeks followed by a 4" one, you can relieve the base curl a bit, but at the risk of some emulsion cracking.
Steve: I'd hazard a guess that Amazon don't shift too many copies of Wilhelm & Brower and that the 'previous customers' here means one or two individuals who bought a load of books about photographic preservation followed by some shit lit for light relief. But maybe Hogwarts can teach you some spells to correct coupler dye fading though...
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Brad Miller
Administrator
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Posts: 17775
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99
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posted 01-13-2004 03:47 AM
I think we're pretty much talking about acetate films here...
I have yet to see an example where storing the film emulsion in was superior to emulsion out, both in regular projecting as well as long term storage. I don't doubt Leo's findings, as he is a professional archivist, but I haven't seen those results here. If I screen a print that hasn't been ran in a year that was wound emulsion in, the focus drift from the head to tail of the reel is unbelieveable, the registration looks like it was printed at Deluxe and the film is badly warped. After a year or so in storage emulsion out, all of these issues go away (except sometimes the warping is permanent). This is the case even when running off of 6000 foot reels...razor sharp focus from end to end of the reel!
When films stored emulsion out are pulled and ran after sitting for a few years, they run fine and dandy for me, just like new. This isn't something I have seen on occasion, but is repeatedly and an absolute. Because of that, I cringe when I get an older title wound emulsion in, because it means I have to park my barstool by the projector and screw with the focus the whole movie!
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