Rustication (architecture)

Rustication refers to 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.