Indigo-dyed bast fibers on parchment

Has anyone observed blue fibers, or identified indigo-dyed bast
fibers, on the surface of parchment or leather objects?  We have
identified indigo-dyed bast fibers on parchment-covered surfaces of
an object purported to date to 1550.  The fibers lay beneath what
appears to be an original paint layer. Any information would be
appreciated.  TIA

James Martin
Director of Analytical Services and Research
Associate Conservator of Paintings
Williamstown Art Conservation Center

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                  Conservation DistList Instance 9:50
                Distributed: Saturday, December 23, 1995
                        Message Id: cdl-9-50-004
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