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Topic: Emulsion Stripping

Jeff Taylor
Jedi Master Film Handler

Posts: 601
From: Chatham, NJ/East Hampton, NY
Registered: Apr 2000

posted 12-17-2001 01:54 PM

Last weekend I got a print in and spent some time re-leadering it and checking the splices. At one point I found 3 rather clumsy tape splices virtually next to eachother in a section of the film where the continuity would not be a problem and decided to replace the short section with one good "neutaper" splice. To avoid losing any more frames than necessary I peeled off the two end tape splices and was amazed when the emulsion came off with them! This was an early 1980's Eastman B/W print of a Paramount title which I PRESUME may have been struck by Technicolor for Universal. The emulsion is pristine otherwise. Anybody ever encounter this before, and why would it happen?

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John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000

posted 12-17-2001 02:13 PM

Some splicing tapes could be so "sticky" that they could cause delamination of the emulsion, especially on older films and with tape that has been on the print for a long time. The "subbing layer" technology that adhere the gelatin emulsion onto the plastic support has greatly improved over the years.

It's also possible that if that 20-year old print were stored improperly (sealed container with excessive heat and humidity), the acetate base could be starting to exhibit "vinegar syndrome" deterioration, which can lead to emulsion delamination.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

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Jeff Taylor
Jedi Master Film Handler

Posts: 601
From: Chatham, NJ/East Hampton, NY
Registered: Apr 2000

posted 12-17-2001 02:20 PM

Thanks, John. To me, as a collector, an "early '80's" print is not very old, but it would take more than my crystal ball to know what kind of tape the perpetrator used, and that was probably the cause. All I know is that it wasn't yellowed or noticeably thicker than normal. Still, I wish I had a penney for every splice I've pulled apart to remake, and this had never happened before.

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Jeff Taylor
Jedi Master Film Handler

Posts: 601
From: Chatham, NJ/East Hampton, NY
Registered: Apr 2000

posted 12-17-2001 02:22 PM

P.S.: I've got a very sensitive nose for VS, and this print had no odor, even out of the shipping container, so I think it's OK on tht score.

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Brad Miller
Administrator

Posts: 17775
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99

posted 12-17-2001 02:46 PM

It's not the tape. There is something that I cannot explain about black and white film stock where once a splice sits on a frame for a length of time (few months) it will take the emulsion off with it. I've tried the cheap crap all the way up to Neumade tape and it happens with all of it.

(Disclaimer, this always happens with acetate stocks. Not sure if it is happening with polyester stocks as well.)

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Leo Enticknap
Film God

Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000

posted 12-20-2001 09:48 AM

Jeff - just because you can't smell vinegar yet doesn't mean that the process of deacetylation (vinegar syndrome) has not started. In fact, it's quite advanced by the time you can smell anything. The easiest way to identify elements in an early stage of vinegar syndrome is to use acid detection (a/d) strips.

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