Odd protective layer applied at one-hour labs.. what's this called?

Discussion in 'Color: Film, Paper, and Chemistry' started by holmburgers, Apr 11, 2012.

  1. holmburgers

    holmburgers Member

    Messages:
    4,423
    Joined:
    Aug 13, 2009
    Location:
    Rochester NY
    Shooter:
    Multi Format
    In the process of organizing all my old negs, I've come across a number of C-41 films that were developed at Walgreens some years back and which have a protective plastic layer laid over them. It's not quite a sleeve, as it doesn't wrap around the sides, but each side has a strip of clear plastic/PET overlaid that's glued to the film along the sprockets. It's fairly easy to peel off, and was obviously applied automatically in the machine before being cut. It's kind of a clever idea actually, but at first sighting I was totally flummoxed!

    I've never noticed this before and have never heard of it. What is this called? I assume it was some implementation by Kodak and I'm curious if the glue used is safe for long term storage, though I'd assume it is.

    Anybody know what I'm talking about? Got a patent number by chance?
     
  2. Ian C

    Ian C Member

    Messages:
    722
    Joined:
    Feb 8, 2009
    Shooter:
    Large Format
    Many optical projection printers that were part of a minilab were designed to handle the original color negative film in a continuous strip when a complete set of prints from the just-developed film was made. Then the film was cut into shorter strips often of 4 frames for 35mm films.

    Later, if reprints were wanted, the lab had to cement handling tabs to the edges of the film to position the frames wanted in the printer as the operator had no other way of positioning the negative due to the design of the machine. The ones I’ve seen were only applied to negatives at the time that reprints were made. I believe that the large grocery/department store that did this to the negatives I refer to used a large Fuji minilab in the 1990s.

    I think that what you have is variation of this idea. If the handling tabs were applied upon the initial develop & print order, then it might be that the particular machine used required handling tabs of all films.

    Sometimes the adhesive bonded too well. I accidently tore a 35mm color negative along the sprocket-hole margin in trying to remove the handling tab in preparation for using it in my enlarger. Of course, the margin along the sprocket holes is quite narrow and it didn’t take much pulling to tear the edge. Ultimately, I was able to completely remove all traces of the adhesive with naphtha.

    I prefered that the lab use equipment that didn't require the glued-on tab.
     
  3. holmburgers

    holmburgers Member

    Messages:
    4,423
    Joined:
    Aug 13, 2009
    Location:
    Rochester NY
    Shooter:
    Multi Format
    Hi Ian,

    I wouldn't describe what I'm seeing as handling tabs per se, simply because they don't extend further than the film. They're only adhered to one row of sprocket-holes per side, so that the protective layer is a flap.

    Does this sound different than what you're referring to? At any rate, it's the same kind of thing and poses the same questions/concerns.
     
  4. Denverdad

    Denverdad Subscriber

    Messages:
    278
    Joined:
    Apr 20, 2009
    Location:
    Superior, Co
    Shooter:
    Medium Format
    I don't know if it has a particular name or not, but yes, I do know what you're talking about! A while back I had occassion to scan some old negatives, and found that some of the strips had that glued-on protective layer you're describing. It was kind of a pain actually, having to deal with that. But at least they had some protection - a few sets of my old photos from the one-hour photo shops had the negatives slipped into the envelope, without any protective covering at all. :sad:

    As for the glue, I wouldn't assume off-hand that it is archival. But in my case at least, after 30-ish years the glue hasn't seemed to have caused any obvious degradation to the film.

    Jeff
     
  5. holmburgers

    holmburgers Member

    Messages:
    4,423
    Joined:
    Aug 13, 2009
    Location:
    Rochester NY
    Shooter:
    Multi Format
    Thanks Jeff,

    Yeah, I was resleeving all the loose negs I came across (a real pain!), but I started just accepting that these negatives are already protected, albeit oddly.

    The reason I assume it's archival is because I don't think Kodak or Fuji would engineer into their system something that isn't, especially considering the brazenness of actually applying glue to your negatives. I suspect there are a number of suitable adhesives that won't degrade any worse than the PET they're adhering. However, a patent describing which glue they used might make me feel a bit better..
     
  6. Mustafa Umut Sarac

    Mustafa Umut Sarac Member

    Messages:
    4,589
    Joined:
    Oct 29, 2006
    Location:
    İstanbul
    Shooter:
    35mm RF
    They were doing the same 25 years ago at Istanbul.
     
  7. MattKing

    MattKing Subscriber

    Messages:
    17,174
    Joined:
    Apr 24, 2005
    Location:
    Delta, BC, Canada
    Shooter:
    Multi Format
    They were probably cheaper than sleeves.