CULTURAL SOFTWARE
                                 P.O. Box 15191
                              Rio Rancho, NM 87174
                                 (505) 891-0438
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    A Note About Paper Labels, Adhesives and
       the Conservation of Photographic Materials . . .

    By popular demand, THE PHOTOARCHIVIST II prints two sizes of labels for
    placement on slides, the backs of prints, negative envelopes and
    sleeves. However, while we carefully listen to our customers' needs, we
    also care about their collections. You may wish to carefully consider
    the wisdom of placing adhesive labels on prints, slides or sleeves if
    the materials are intended to be long-lived or permanent.

    Archivists and photographic conservators do not recommend using
    adhesive labels because of problems (described below) with acid paper
    and adhesives.  Cultural Software produces an institutional system for
    museums, archives and libraries.  It does not print on adhesive labels
    because these institutions will not use them on their permanent
    collections.

    A Little Paper Label Chemistry

    With few exceptions, paper (and paper products including paper slide
    mounts) is made from wood processed into pulp with sulfuric acid and
    other chemicals.  The pulping process leaves microscopic crystals of
    acid in the paper that become active (and destructive) upon exposure to
    humidity, temperature and light.  Additionally, wood contains three
    naturally acidic componentsÿ-ÿcellulose, hemi-cellulose and lignin.
    Acid content is why 90+% of all paper productsÿ-ÿfrom your morning
    newspaper to paperback novels and booksÿ-ÿbecome brittle, yellow and
    deteriorate over time.

    Acid-free labels are available through some suppliers. They are made
    from chemically stable (100% cotton) paper or acid-neutralized
    (buffered) paper.  However, the staff at Cultural Software will not use
    or recommend these labels for several reasons: (1) they are
    unreasonably expensive; (2) they are often in short supply; (3) some
    batches do not meet Library of Congress standards for permanence; (4)
    some are made of stable paper, but contain unstable dyes (colors); and
    (5) all of them rely on adhesives.

    An Adhesive Primer

    Most adhesives ("Scotch" tape or drymount tissue for instance) are
    chemically destructive in the short or long term. They yellow, stain,
    resin-impregnate or weaken paper. All adhesives eventually dry out,
    release and drop off.  Unfortunately, the more benign the adhesive, the
    shorter its "sticking" life. This can be particularly disturbing if a
    label drops off a slide in a carousel and jams the projector. Or, if
    you open a file drawer, years after labeling prints or sleeves, and
    find the labels on the bottom of the drawer.

    It is perfectly acceptable to use labels on duplicate copy prints and
    on materials where permanence is not important.  However, most
    archivists recommend marking slide mounts, negative envelopes and
    prints by hand, in pencil instead of ink. Other tips are to

    (1) use negative and print envelopes made of acid-free paper (available
        from Light Impressions, the Hollinger Corporation, University
        Supply and other sources) and

    (2) avoid paper slide mounts, which are made of acidic paper and
        adhesives.

    Thanks.