For works that are to stand damp and weather, consists in a first thin painting with linseed oil and red-lead, massicot, or litharge; but for in-door and dry work clear-colling is preferred, which consists in using size of glue instead of oil in the priming, but it is liable to peel and scale off in damp places. Work thus prepared, smoothed, and primed, is ready for the painting and finishing; but in no case should wood in a wet state, or green and unseasoned wood, be painted in oil; the consequence in such cases being either the speedy decaying of the wood, or the scaling and casting off of the paint. The usual process of oil-painting requires the ground white lead to be diluted with linseed oil and hardly any spirit of turpentine for the first coat; equal quantities of both for the second coat, and for the third or finishing coat twice as much turpentine as linseed oil; and still more of the turpentine in proportion for dead flatting according to the tints and colours. For work exposed to weather the turpentine should be wholly omitted, and oil alone employed. When painting external work in imitation of free-stone it is a valuable practice to strew the second or last full coat of oil paint while wet with fine washed and sifted sand, which adhering and drying on with the paint, forms a durable coat, exactly resembling stone and protecting the work from weather. Powdered talc, gold and silver leaf, bronzes, smalts and colours, are similarly employed in ornamental works.