Faded ink

Kathie Bordelon <kbordelo<-a t->mcneese< . >edu> writes

>Is there anyway to "bring out" iron gall ink on paper that has
>faded?

You will find a number of methods for intensifying degraded iron
gall inks in the literature, some of them very effective and clever,
but you should never be tempted to apply them to archival material,
for several reasons:

    1.  They may have a deleterious effect on the paper of the
        document.

    2.  They may alter with time, and actually make the document
        less legible in the long term.

    3.  They will almost certainly make the application of
        non-interventive techniques for image intensification
        ineffective.

    4.  You will have altered a historical document, and thereby
        reduced any evidential value which it might formerly have
        possessed.

Fortunately, most iron gall inks, even if barely still perceptible,
can be successfully revealed by the use of ultraviolet fluorescence
photography.   Most papers, even those manufactured before the
introduction of optical whiteners in the 1950s, exhibit a weak
fluorescence under long-wave ultraviolet light.  Traces of iron
compounds quench this fluorescence, and the areas formerly carrying
ink appear dark against a lighter background.    It takes some skill
to get good results, but all that is required is a source of
long-wave ultraviolet light (the more common type of UV lamp) and a
camera fitted with an ordinary UV absorbing filter (haze filter) and
a fairly fast pan B&W film. Care should be taken to avoid prolonged
exposure of the eyes to UV light, but the exposure required will not
adversely affect the document.

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                  Conservation DistList Instance 10:83
                  Distributed: Tuesday, March 25, 1997
                       Message Id: cdl-10-83-003
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