Combined gas-chromatography and mass spectrometry was used for identifying material extracted from 16 19th-century tracing papers from the national maritime museum collection. The components were non-drying oil, or fat, drying oil, pine resin, and an unknown which could be oil of turpentine used as solvent. Varnishes from a 18th-century globe were also studied. This contained pine resin, sandarac, and mastic. The absence of drying oils indicated that these were probably used in alcoholic solutions. References.