Metallic permanent marker

We recently acquired some posters on lightly coated white paper
stock.  In addition to the printer ink (likely laser printed),
autographs have been added to the poster face in metallic Sharpie
(or Sharpie type maker).

Has anyone encountered this media?

Are there additional/specific deterioration or preservation issues
re: metallic makers as opposed to the typical/non-metallic
Sharpie/Sharpie-type markers?

Joanna P McMann
Assistant Conservator
Archives of the NWT
Prince of Wales Northern Heritage Centre
Department of Education, Culture and Employment
Government of the Northwest Territories


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                  Conservation DistList Instance 29:14
                  Distributed: Sunday, August 23, 2015
                       Message Id: cdl-29-14-017
                                  ***