PAINTING AND MURAL DECORATION (cont.)
Technical Methods of Roman Mural Painting.
Technical Methods of the Romans. Much has been written on this subject, and the most varying opinions have been expressed. The real fact appears to be that several methods were employed in each painting. First, the ground of the required colour was laid on while the stucco was still moist. This ground therefore was true fresco or "fresco buono." On this, when dry, the various pictures and ornaments were painted in tempera That the pictures themselves were not in true fresco is shown: (1) because the coloured ground always exists under the pictures; (2) by the wide distances apart of the "fresco edges" or joinings in the stucco, showing that a much larger area of stucco applied at once than could have been covered with the frequently elaborate paintings before the stucco was dry; (3) by the fact that many of the brilliant pigments were not such as could have been used upon moist stucco. The next point is how these tempera paintings on the fresco ground were fixed so as to last for nearly eighteen hundred years uninjured by the damp which necessarily soaked through into the soil and ashes in which they were buried. This was probably effected by the "encaustic" process (engkausis [Gk.]). When the painting was finished and dry, hot melted wax was brushed all over it; and then a red hot iron or brazier of burning charcoal was held near the face of the wall till, bit by bit, all the wax disappeared from the surface and soaked thoroughly into the absorbent stucco, thus fixing the pigments with a vehicle that could stand the effects of damp. This application of hot wax appears to have been repeated more than once. The extreme smoothness of the fresco ground under the tempers pictures seems to show that the ground itself was both waxed and polished before the pictures were painted over it. By another method of encaustic the pigments themselves were mixed with hot wax, probably rendered more fluid and easy to work by the addition of some mineral spirit or essential oil. The final application of heat to the painted surface blended the colours together and fixed them and into the absorbent stucco ground. Vitruvius (vii. 9) describes the former process, in which the wax was applied after the colours were laid on the wall. According to him this was necessary in order to prevent the painted surface becoming patchy, especially in the case of the red ground made of vermillion, an oxide of mercury. This, as well as the evidence of the paintings themselves, shows that Pliny is mistaken in asserting that encaustic work could not be used for wall.[Footnote 43-1] Vitruvius (vii.) also gives an interesting account of the great care that was needed in preparing stucco for painting. Three coats of old slaked lime and sand were first to be laid, and then three more coats mixed with pounded white marble, each coat of more finely powdered marble than the one beneath; the last coat was to be polished till it gave a reflexion like a mirror. Damp or external walls were to be built hollow, and the cavity ventilated; this was sometimes done, e.g., in the Palatine villa, by facing the wall inside with hollow bricks or tiles, on which the stucco was laid. Vitruvius, who probably died shortly before died shortly before the Christian era, laments the decay of taste in his time, much as Pliny does ; he specially deprecates the use of gaudy red lead, and the sham architectural paintings in which candelabra, reeds and other incongruities are made to support heavy cornices and roofs of buildings. He complains also of the novel taste for expensive but inartistic colours, such as purple and azure.[Footnote 43-2]
(43-1) His remarks on the subject (xxxv.11) are quite unintelligible.
(43-2) Gell and Gandy, Pompeiana (1817-19 and 1835); Herculaneum et Pompei, Recueil des Peintures, &c., Paris (1870-72); Jorio, Descr. des Peintures antiques (1825); Renier et Perrot, Les Peintures du Palatin (1870); Hittorf, Arabesques of the Ancients; Real Museo Borbonico (1824 et seq.); Mau, Gesch. der Decorativen in Pompei (1882); Donner and Helbig, Wandgemälde der vom Vesuv verschütteten Städte (1868); Ann. and Bull. dell Inst. di Cor. Arch di Roma (various years); Ternite and Müller, Wandgemälde aus Pompei; Zahn, Gemälde aus Pompei (1828); Rochette, Peintures de Pompei (1844-59); Mazois, Ruines de Pompei (1824); Overbeck, Pompei, &c. (1856); Revue Archéol., vol. ii. (1845); Le Pitture antiche dEncolano (1757-79) Fiorelli, Pomp. ant. Hist. (1860-4); Sogliano, Le Pitture murali Campane (1880); Paderni, Dipinti, &c., di Pompei, Ercolano, &c. (1865); Caylus, La Peinture à lEncaustique (1755); and Minervini, Bull. arch. Napol. (1852-59). See also the list of works on Greek painting.
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