Pastiglia

Pastiglia [paˈstiʎʎa], an Italian term meaning "pastework", is low relief decoration, normally modelled in gesso or white lead, applied to build up a surface that may then be gilded or painted, or left plain. The technique was used in a variety of ways in Italy during the Renaissance. The term is mostly found in English applied to gilded work on picture frames or small pieces of furniture such as wooden caskets and cassoni, and also on areas of panel paintings, but there is some divergence as to the meaning of the term between these specialisms.

On frames and furniture the technique is in origin a cheaper imitation of woodcarving, metalwork or ivory carving techniques. Within paintings, the technique gives areas with a three-dimensional effect, usually those representing inanimate objects, such as foliage decoration on architectural surrounds, halos and details of dress, rather than parts of figures. In white lead pastiglia on caskets, the subject matter is usually classical, with a special emphasis on stories from Ancient Roman history.

In reference to work on picture frames and paintings moulded and gilded gesso is still commonly described as pastiglia, but in recent decades writers on furniture and the decorative arts tend to distinguish between this and "true" pastiglia, or white lead pastiglia which is defined as being made from white lead powder, made by combining powdered lead and vinegar in an anaerobic environment, bound with egg white. White lead bound with oil or egg yolk was also the most common pigment for white paint. White lead pastiglia is very delicate and used for small areas only, but can produce very fine detail. It was mainly used on small caskets and boxes. Sections were typically pre-moulded, doubtless from metal matrices to judge from the crisp detail, and glued on when hard. This was usually left unpainted, when it looked like carved ivory, which had been widely used to decorate boxes in Italy, by the Embriachi and others, but was by now less used, partly because it was too rare and expensive. The wood from which the main box was made was normally alder. It seems the term pastiglia for this only dates to the 17th century, after the technique had largely fallen from use. A scented variant called pasta di muschio ("musk paste") mixed musk perfume with the white lead, and was thought to be "aphrodisiacal", and so used for caskets given at a marriage, and also other objects such as inkwells and frames for hand mirrors.

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