In the ancient civilizations in and around the Mediterranean, artisans used vegetable oils as the working medium for painting. Air-drying paint formulations using oils of castor, hempseed, pine nut, poppy and walnut have been recorded. Linseed oil generally was not used due to its tendency to slowly dry, darken and crack over time, unlike mastic and waxes. Once thickened, the oils became resinous and could be used as a varnish to seal and protect artisans’ paintings from water.
Early Christian Monks maintained meticulous records and used these same formulations and techniques for artwork paints and varnishes as well as for indicia inks. Linseed oil was commonly used for indicia document recording by scribes instead of olive oil – which took an excessively long time to dry. Oil-based paints were also commonly used for decoration upon outdoor exposed wood surfaces due to its tough waterproofing nature, just as in modern day.