[ varnishes ]
Musical instruments made of wood need to be protected from dangers like ageing, humidity and wear. So luthiers have always used some kind of protective coating.The first protective finishes were oil and wax. But in the age of Alchemy they were soon replaced by complicated concoctions that were often kept as professional secrets.
In the mid 18th century a revolutionary new varnish appeared. French Polish is made from shellac resin and was first developed for military use.
Synthetic Finishes may be very resistant to water and heat but may not always meet the unusual requirements of the guitar maker.

