A review of the analytical procedures currently employed in the laboratory of the Scientific Department at The National Gallery for the analysis of resin-oil varnish mixtures is given. In addition, critical comments are offered on techniques which have been examined but were found to be either partially or totally unsatisfactory. An outline of the application of such methods is given, a fuller treatment of which, together with specific examples, was made at the conference. Emphasis is placed upon gas-chromatographic methods and gas-chromatography linked with mass spectrometry.