Mural Decoration dates from very ancient times. The Egyptian and Etruscan monuments form an integral and important part of the history of Painting (q.v.), and have helped to mould the development of certain styles of art (see ARABESQUE). Incised work and reliefs have been largely employed. The Greeks tinted their temples and 'picked out' their sculptured friezes and pediments with colour; coloured bricks were used in Assyrian, and wall tiles (see POTTERY) in Moslem, architecture. Some of the Roman walls were built of tufa and red brick, coloured brick, terra-cotta, and variegated arrangements of marble were largely used in Italy. The plaster-work known as Sgraffito (q.v.) is especially adapted for this use. Many English churches of the mediæval period have been built of flint and stone, and much Tudor work of parti-coloured brick. Distemper and Fresco are described in separate articles; water glass is a silicate process of which there is an example in the Houses of Parliament. Mosaic-work is extensively used in floors and ceilings, but also occasionally employed in mural decoration. The dado of the Albert Memorial Chapel at Windsor is composed of slabs of inlaid marble hatched with coloured gold cement. See also TAPESTRY, WALL-PAPER.
Another system is that known as Encaustic Painting (Gr. encaustikê, 'fixed by fire'), a manner of mural painting with a medium composed principally of wax, practised by the ancients. As the name implied that fire was used in the execution, some have been led to suppose that encaustic painting was the same as enamel painting; but notices by Pliny and other writers show clearly that it was a species of painting in which the chief ingredient used for uniting and fixing the colours was wax dissolved by heat. Various attempts have been made in modern times to revive it. About the middle of the 18th century Count Caylus and Bachelier, and in 1792 Mrs Hooker of Rottingdean, under the name of Emma Jane Greenland, made various successful experiments with this view. Encaustic painting was again taken up in Germany under the patronage of Louis I. of Bavaria, who commissioned Louis Schnorr to execute a series of historical subjects on the walls of the royal palace, Munich. For preparing her medium Mrs Hooker dissolved gum-arabic in water, afterwards adding gum-mastic, which was dissolved by stirring and boiling, and when the mixture had reached the boiling-point she put in the wax. After painting the picture, she passed a thin coating of melted wax over it with a hard brush, and then drew over the surface an iron—for ironing linen—moderately heated. After the picture cooled it was rubbed with a fine linen cloth. The German method is somewhat similar, but some other ingredients are used; among these, potash with the wax; and, in place of an iron being passed over the surface, the wax is brought to the surface by a vessel containing fire being held at a little distance from the picture. It is also possible to employ a medium made of a mixture of turpentine and beeswax sufficiently plastic to be worked like oil. A modification of the system was also devised by Mr Gambier-Parry, and is known as Spirit Fresco. By his method the walls are coated with wax and gum compounded with spirit of lavender. The colours are ground with the same medium.