An isolation coat is a clear, non-removable coating that serves to physically separate the paint surface from the removable varnish. The isolation coat serves two purposes: (1)To protect the painting if/or when the varnish is removed by separating the pigmented area of the painting from the solvents used in removal. (2)To seal any absorbent areas in order to create an even surface on which to apply the varnish.
An isolation coat can be very beneficial to the preservation of a piece of artwork but it is not for every painting. The decision of applying an isolation coat is first an aesthetic decision: Will this serve the purpose of the work? Secondly, are the changes created by the application of an isolation coat and subsequent varnish understood and anticipated? These are important questions to consider as the isolation coat will become a permanent part of the painting.
