Рустикальная кладка: техника текстурирования камня

Masonry technique of texturing

Rustication is a range of masonry techniques used in classical architecture giving visible surfaces a finish texture that contrasts with smooth, squared block masonry called ashlar. The visible face of each individual block is cut back around the edges to make its size and placing very clear. In addition the central part of the face of each block may be given a deliberately rough or patterned surface. Rusticated masonry is usually "dressed", or squared off neatly, on all sides of the stones except the face that will be visible when the stone is put in place. This is given wide joints that emphasize the edges of each block, by angling the edges ("channel jointed"), or dropping them back a little. The main part of the exposed face may be worked flat and smooth or left with, or worked, to give a more or less rough or patterned surface. Rustication is often used to give visual weight to the ground floor in contrast to smooth ashlar above. Though intended to convey a "rustic" simplicity, the finish is highly artificial, and the faces of the stones often carefully worked to achieve an appearance of a coarse finish. Rustication was used in ancient times, but became especially popular in the revived classical styles of Italian Renaissance architecture and that of subsequent periods, particularly in the lower floors of secular buildings. It remains in use in some modern architecture. Similar finishes are very common in medieval architecture, especially in castles, walls and similar buildings, but here it merely arises from an unwillingness to spend the extra money required for ashlar masonry in a particular building, and lacks the deliberate emphasis on the joints between blocks. Though it often achieves a decorative effect, this is something of a by product, and the exploitation for architectural effect within a single building of contrasts between rusticated and ashlar surfaces is rarely seen. In some buildings, such as the Palazzo Vecchio in Florence (begun 1298) something other than cost saving is at play, and this may be the association of the technique with the display of power and strength, from its use in military architecture. Rough finishes on stone are also very common in architecture outside the European tradition, but these too would generally not be called rustication. For example, the bases of Japanese castles and other fortifications usually use rough stone, often very attractively.

Although rustication is known from a few buildings of Greek and Roman antiquity, for example Rome's Porta Maggiore, the method first became popular during the Renaissance, when the stone work of lower floors and sometimes entire facades of buildings were finished in this manner. It was generally used for secular buildings, and has always remained uncommon in churches, perhaps through a lingering association with the architecture of military power; there are exceptions, such as St Giles in the Fields, London (1730–34). Probably the earliest and most influential example is the Palazzo Medici Riccardi in Florence, built between 1444 and 1484, with two contrasting rusticated finishes. The ground floor has an irregular and genuinely rugged appearance, with a variation in the degree to which parts of the faces of blocks project from the wall that is rarely equalled later. Above, the rustication is merely to emphasize the individual blocks, and the faces are all smooth and even. Also in Florence, Palazzo Strozzi, begun 1489, with large oblong rounded cushions, and the front of the Palazzo Pitti, begun 1458, rusticated their whole facades in the same style. These facades only used the classical orders in mullions and aedicules, with arched forms in rustication the main relief from the massive flat walls. The Palazzo Rucellai, probably of the 1460s, begins to classicize such facades, using smooth faced rustication throughout, except for the pilasters at each level. In Rome, Donato Bramante's Palazzo Caprini ("House of Raphael", by 1510, now destroyed) provided a standard model for the integration of rustication with the orders. Here the obvious strength of a blind arched arcade with emphatic voussoirs on the rusticated ground storey (in fact using stucco) gave reassuring support to the upper storey's paired Doric columns standing on rusticated piers, set against a smooth wall. The first major Renaissance building in Spain, the Palace of Charles V in Granada (1527), had a deeply rusticated ground floor facade with regular rounded cushions. The technique was enthusiastically taken up by the next generation of Mannerist architects, with Giulio Romano in the lead. Most early examples of this "rustic" style are therefore built for sophisticated patrons in the leading centres of taste. Giulio's Palazzo Maccarani Stati in Rome and Palazzo Te in Mantua expand the voussoirs still further, and the courtyard in Mantua plays games with the technique, with some blocks ashlar, other projecting further than the rest, and larger blocks placed higher than smaller ones. The Mannerist architectural writer Sebastiano Serlio and others of his generation enjoyed the play between rusticated and finished architectural elements. In the woodcut of a doorway from Serlio's 1537 treatise, the banded rustication of the wall is carried right across the attached column and the moldings of the doorway surround, binding together all the elements. The Italians brought in to expand the Palace of Fontainebleau introduced the technique to France. Its spread to Germany and England took longer, but by about the end of the 16th century it had reached all parts of Europe. In his Banqueting House in London (1619), Inigo Jones gave a lightly rusticated surface texture to emphasize the blocks on both storeys, and to unify them behind his orders of pilasters and columns. During the 18th century, following the Palladian revival, rustication was widely used on the ground floors of large buildings, as its contrived appearance of simplicity and solidity contrasted well to the carved ornamental stonework and columns of the floors above: "Rustication became almost obligatory in all 18th and 19th century public buildings in Europe and the USA". A ground floor with rustication, especially in an English mansion such as Kedleston Hall, is sometimes referred to as the "rustic floor", in order to distinguish it from the piano nobile above. As well as uses emphasizing the horizontal, rustication is often used in relatively narrow vertical bands, on the quoins at corners or elsewhere. Rustication may also be confined to the surrounds of arches, doors or windows, especially at the top. In these and other situations where rustication stops horizontally, the edge is usually made up of vertically alternating long and short blocks. Rustication therefore often reverses the patterns of medieval and later vernacular architecture, where roughly dressed wall surfaces often contrast with ashlar quoins and frames to openings. Architectural books by authors such as James Gibbs and William Chambers set out detailed recommendations for the proportions of the blocks in relation to columns in the same facade, and the proportion of the block that a widened joint should occupy, though their prescriptions differ, and were not always followed by architects. The small Turner Mausoleum at Kirkleatham by James Gibbs (1740) has an unusually large area vermiculated, over half of the main level. When the shapes join up to form a network, the style is called "reticulated". Also associated with gardens is "cyclopian" rustication, where the blocks are very large and irregular, as though placed by giants, and "rock work", where surfaces are built up of rough rocks not placed in regular courses at all. This last goes beyond rustication, and is found in fountains and follies, and later rockeries for planting. In "prismatic rustication" the blocks are dressed at an angle near each edge, giving a prism like shape. Where the faces rise to a single point, this is often known by terms using "diamond", and is covered below. They may also, usually in blocks that are oblong rather than square, rise to a ridge in the centre. Both types are illustrated, with several others, by Serlio.

Various types of other patterns in masonry surfaces are sometimes called rustication. These include "diamond point" or "diamond rustication" where the face of each stone is a low pyramid facing out. Rustication of a wooden exterior consists of three basic steps. First, the wood is cut, sanded and prepared with beveled grooves that make each plank appear as if it were a series of stone blocks. Second, the wood is painted with a thick coat of paint. Third, while the paint is still wet, sand is thrown or air blasted onto the planks until no more sand will stick. After the paint dries the plank is ready for use. In Central Europe, especially the Czech Republic, feigned rustication in sgraffito (decoration by scraping away one colour of coating on an exterior to show another beneath) is a feature from the late Renaissance onwards, continuing into the 20th century. Often "prismatic" or "diamond" rustication is imitated.