Fresco is a technique of mural painting executed upon freshly laid ("wet") lime plaster. Water is used as the vehicle for the dry-powder pigment to merge with the plaster, and with the setting of the plaster, the painting becomes an integral part of the wall. The word fresco is derived from the Italian adjective fresco meaning "fresh", and may thus be contrasted with fresco-secco or secco mural painting techniques, which are applied to dried plaster, to supplement painting in fresco. The fresco technique has been employed since antiquity and is closely associated with Italian Renaissance painting.
A mural is any piece of graphic artwork that is painted or applied directly to a wall, ceiling or other permanent substrate. Mural techniques include fresco, mosaic, graffiti and marouflage.
Impasto is a technique used in painting, where paint is laid on an area of the surface thickly, usually thick enough that the brush or painting-knife strokes are visible. Paint can also be mixed right on the canvas. When dry, impasto provides texture; the paint appears to be coming out of the canvas.
Plaster is a building material used for the protective or decorative coating of walls and ceilings and for moulding and casting decorative elements. In English, "plaster" usually means a material used for the interiors of buildings, while "render" commonly refers to external applications. The term stucco refers to plasterwork that is worked in some way to produce relief decoration, rather than flat surfaces.
The Gambier Parry process is a development of the classical technique of fresco for painting murals, named for Thomas Gambier Parry.
Scagliola is a type of fine plaster used in architecture and sculpture. The same term identifies the technique for producing columns, sculptures, and other architectural elements that resemble inlays in marble. The scagliola technique came into fashion in 17th-century Tuscany as an effective substitute for costly marble inlays, the pietra dura works created for the Medici family in Florence. The use of scagliola declined in the 20th century.
Kerala mural paintings are the frescos depicting Hindu mythology in Kerala. Ancient temples and palaces in Kerala, India, display an abounding tradition of mural paintings mostly dating back between the 9th to 12th centuries CE when this form of art enjoyed royal patronage.
In art, an underpainting is an initial layer of paint applied to a ground, which serves as a base for subsequent layers of paint. Underpaintings are often monochromatic and help to define color values for later painting. Underpainting gets its name because it is painting that is intended to be painted over in a system of working in layers.
Sgraffito is a technique either of wall decor, produced by applying layers of plaster tinted in contrasting colours to a moistened surface, or in pottery, by applying to an unfired ceramic body two successive layers of contrasting slip or glaze, and then in either case scratching so as to reveal parts of the underlying layer. The Italian past participle sgraffiato is also used, especially of pottery.
Roughcast or pebbledash is a coarse plaster surface used on outside walls that consists of lime and sometimes cement mixed with sand, small gravel and often pebbles or shells. The materials are mixed into a slurry and are then thrown at the working surface with a trowel or scoop. The idea is to maintain an even spread, free from lumps, ridges or runs and without missing any background. Roughcasting incorporates the stones in the mix, whereas pebbledashing adds them on top.
Sinopia is a dark reddish-brown natural earth pigment, whose reddish colour comes from hematite, a dehydrated form of iron oxide. It was widely used in Classical Antiquity and the Middle Ages for painting, and during the Renaissance it was often used on the rough initial layer of plaster for the underdrawing for a fresco. The word came to be used both for the pigment and for the preparatory drawing itself, which may be revealed when a fresco is stripped from its wall for transfer.
Putlog holes or putlock holes are small holes made in the walls of structures to receive the ends of poles or beams, called putlogs or putlocks, to support a scaffolding. Putlog holes may extend through a wall to provide staging on both sides of the wall.
A glaze is a thin transparent or semi-transparent layer on a painting which modifies the appearance of the underlying paint layer. Glazes can change the chroma, value, hue and texture of a surface. Glazes consist of a great amount of binding medium in relation to a very small amount of pigment. Drying time will depend on the amount and type of paint medium used in the glaze. The medium, base, or vehicle is the mixture to which the dry pigment is added. Different media can increase or decrease the rate at which oil paints dry.
Béton brut is architectural concrete that is left unfinished after being cast, displaying the patterns and seams imprinted on it by the formwork. Béton brut is not a material itself, but rather a way of using concrete. The term comes from French and means "raw concrete".
Underdrawing is a preparatory drawing done on a painting ground before paint is applied, for example, an imprimatura or an underpainting. Underdrawing was used extensively by 15th century painters like Jan van Eyck and Rogier van der Weyden. These artists "underdrew" with a brush, using hatching strokes for shading, using water-based black paint, before underpainting and overpainting with oils. Cennino D'Andrea Cennini describes a different type of underdrawing, made with graded tones rather than hatching, for egg tempera.
Distemper is a decorative paint and a historical medium for painting pictures, and contrasted with tempera. The binder may be glues of vegetable or animal origin. Soft distemper is not abrasion resistant and may include binders such as chalk, ground pigments, and animal glue. Hard distemper is stronger and wear-resistant and can include casein or linseed oil as binders.
Buon fresco is a fresco painting technique in which alkaline-resistant pigments, ground in water, are applied to wet plaster.
In masonry, mortar joints are the spaces between bricks, concrete blocks, or glass blocks, that are filled with mortar or grout. If the surface of the masonry remains unplastered, the joints contribute significantly to the appearance of the masonry. Mortar joints can be made in a series of different fashions, but the most common ones are raked, grapevine, extruded, concave, V, struck, flush, weathered and beaded.
The Hornemann Institute - Centre of the Preservation of World Cultural Heritage was founded in December 1998 and registered as official project for the German world exhibition EXPO 2000 "World Cultural Heritage - A Global Challenge". Since 2003 the Hornemann Institute is state-funded institute of the University of Applied Sciences und Arts Hildesheim/Holzminden/Göttingen (HAWK). The institute's primary field of activity focuses on worldwide knowledge transfer and further education in the field of conservation and restoration with new media.
The detachment of wall paintings involves the removal of a wall painting from the structure of which it formed part. While detachment was once a common practice, the preservation of art in situ is now preferred, and detachment is now largely restricted to cases where the only alternative is total loss. According to the International Council on Monuments and Sites (ICOMOS):
Detachment and transfer are dangerous, drastic and irreversible operations that severely affect the physical composition, material structure and aesthetic characteristics of wall paintings. These operations are, therefore, only justifiable in extreme cases when all options of in situ treatment are not viable. Should such situations occur, decisions involving detachment and transfer should always be taken by a team of professionals, rather than by the individual who is carrying out the conservation work. Detached paintings should be replaced in their original location whenever possible. Special measures should be taken for the protection and maintenance of detached paintings, and for the prevention of their theft and dispersion. The application of a covering layer concealing an existing decoration, carried out with the intention of preventing damage or destruction by exposure to an inhospitable environment, should be executed with materials compatible with the wall painting, and in a way that will permit future uncovering.
