UV scanning of parchment

I am posting this on behalf of a group of students at the Worcester
Polytechnic Institute.

    We are students at Worcester Polytechnic Institute (WPI) and we
    are currently working on our Major Qualifying Project (MQP), our
    senior year project. The topic of research is ultraviolet
    scanning of parchments. Degraded and moldy parchments are often
    difficult to read, but UV illumination usually improves
    readability of them. The goal of this project is to implement a
    manuscript scanning system based on UV illumination. By scanning
    a manuscript with such an UV scanner, a readable digitized copy
    will be produced, as an alternative to repeated handing of the
    original document and exposure of it to ultraviolet light.

    We were wondering if anyone has any information or insight as to
    why it is possible to see writing underneath the mold by shining
    a UV source over it. Without using UV light, you can only
    observe the mold--you cannot look through the mold and see the
    text.  Furthermore, even with the UV light reaching the text
    underneath the mold, causing the tannin in the iron gall ink to
    fluoresce, we are puzzled as to why visible light could
    penetrate through the mold. Does mold/fungi have a transparent
    property in the presence of a UV source?  If you have any
    information regarding this topic or anything else, please
    contact us. Any help would be greatly appreciated.

    Cindy Chung <cchung [at] wpi__edu>
    Billy Fratelli
    Tak Hoi Lam

Babette Gehnrich
Chief Conservator
American Antiquarian Society
185 Salisbury Street
Worcester, Ma 01609
508-471-2169
Fax: 508-753-3311


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                  Conservation DistList Instance 16:24
               Distributed: Thursday, September 26, 2002
                       Message Id: cdl-16-24-010
                                  ***