Uglow is best known today as a painter of the figure, particularly of female nudes, as well as portraits, still lifes and some introspective landscapes. His ostensibly simple compositions usually consist of a single figure in a setting emptied of extraneous detail; a typical still life may feature a single piece of fruit on a plain tabletop.
With a meticulous method of painting directly from life, Uglow frequently took months or years to complete a painting. Planes are articulated very precisely, edges are sharply defined, and colours are differentiated with great subtlety. His type of realism has its basis in geometry, starting with the proportion of the canvas. Uglow preferred that the canvas be a square, a golden rectangle, or a rectangle of exact root value, as is the case with the Root Five Nude (1976). He then carried out careful measurements at every stage of painting, a method Coldstream had imparted to him and which is identified with the painters of the Euston Road School. Standing before the subject to be painted, Uglow registered measurements by means of a metal instrument of his own design (derived from a modified music stand); with one eye closed and with the arm of the instrument against his cheek, keeping the calibrations at a constant distance from the eye, the artist could take the measure of an object or interval to compare against other objects or intervals he saw before him. Such empirical measurements enable an artist to paint what the eye sees without the use of conventional perspective. The surfaces of Uglow’s paintings carry many small horizontal and vertical markings, where he recorded these coordinates so that they could be verified against reality.