[Table of Contents] [Search]


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Disappearing Ink



             ***********************************************
          CENTRAL NEW YORK BOOK ARTS: TRADITIONAL TO INNOVATIVE
           See The Exhibition Online, And Order Your Catalog.
                      <http://www.philobiblon.com>
             ***********************************************

Gallotannic inks are often pH sensitive, fading with the deacidification and
buffering of a paper substrate for example. If you take separate pH readings
of the stains and of the unstained parchment, and, as is likely, their pH's
vary markedly, you might deacidify the stains locally, raising their pH to
that of the unstained parchment. This process, if the stains substantially
penetrate the parchment, may need to be undertaken from both recto and verso
and repeated. In any case I'd use a non-aqueous solution (to minimize
distortion and aid penetration), doing a minute test spot first of course.
This will often lighten the stains, sometimes to near disappearance. You do
want to match pH's as closely as possible. Allow at least 24 hours after
deacidification before judging the full effect.
The ink should also fade on exposure to light (sunlight, or better, for the
sake of control, daylight spectrum fluorescent), using an opaque mask to
protect the unstained parchment and controlling for heat and humidity under
the light source.
I would be very hesitant to scrape the stains, thus thinning and opening the
surface of the parchment locally. The procedure is not reversible and the
resulting damage can pose problems of it's own. Certainly it shouldn't be
justified if the aim of the stain removal is simply cosmetic.
Lastly, it is probably unreasonable to expect more than a substantial
reduction in the color of the stains; perhaps total eradication is not
necessary? Best
James


Best,
James

             ***********************************************
            BOOK_ARTS-L: The listserv for all the book arts.
      For subscription information, the Archive, and other related
            resources and links go to the Book_Arts-L FAQ at:
                      <http://www.philobiblon.com>

        To unsubscribe, type the following into the message body:
        UNSUB Book_Arts-L AND SEND TO: LISTSERV@LISTSERV.SYR.EDU
 Or click here <mailto:listserv@listserv.syr.edu?body=unsub book_arts-l>
             ***********************************************


[Subject index] [Index for current month] [Table of Contents] [Search]