William Berwick

This article describes the work of William Berwick who was at the time Restorer of Ancient Document at Library of Congress. He used so called silking techniques which have since been proven less than desirable.  Nevertheless, this short article is worth reading.

Surgeon to Worn-Out Documents and Books

http://cool.conservation-us.org/coolaic/sg/bpg/annual/v14/bp14-02.html (describes the current methods of restoration)