FRESCO

Painting is painting in water colours on a wall covered with wet or fresh lime or gypsum. Only those colours can be used which are not affected by the lime, i.e. mineral colours, etc., and the painting is done from a paper cartoon the exact size of the fresco. It has to be done in sections, and each section has to be finished right off, as it cannot be retouched after the plaster is once dry. It is a very ancient art, being well known to the Egyptians, Romans, Mexicans, etc., and was reintroduced into Italy in the 15th century.