Although in theory it is very simple, in practice glazing can be a very complex undertaking. Glazes cannot be used indiscriminately and were always restricted to specific passages of the technique of painting on a wet sheet for children composition. To begin with, there is nothing to be gained by glazing with neutral grays or dull colors.
Grays are far more effective when they are created with opaque or semi-opaque earth colors or black admixed with white. Glazing was utilized for two reasons. One, artists of the past had very few of the brilliant colors that are available today. For example, strong purples, greens and oranges were either rare and unstable or could be mixed with available pigments. For example, purple was approximated by glazing blue over a reddish underpainting or vice a versa. Two, glazing creates, as we have said, an extraordinarily luminosity impossible to achieve otherwise. Oil on canvas, 208 x 171 cm.
This detail of an unfinished painting by the Italian painter Andrea de Sarto shows the beginning of the working-up stage. The red drapery, which has been modeled with flat tones of vermilion and black, would have been successively glazed with madder lake. The sleeves have been modeled with light yellow and dull green and most probably would have been be glazed with verdigris, a deep and lustrous green pigment. Glazing, however, has more than one drawback.
It is difficult to anticipate the final chromatic effect of the glazed area with respect to the overall harmony of the finished work. Due to its transparency a glaze produces an optical depth that attracts the viewer’s eye more than the surrounding layers of opaque paint that usually cover the great part of painted surface of the canvas. Today, there are various informative studies which make reference to glazing in Vermeer’s painting. Reconstruction of Vermeer’s Girl with a Red Hat by Jonathan Janson, author of Essential Vermeer. A superbly conserved example of glazing can be found in Vermeer’s Girl with a Red Hat. In the reconstruction to the left, various stages of the seventeenth-century multi-stage painting process can be observed. The red hat, according to common practice for painting bright red objects, is first modeled with shades of pure vermilion and black.
The background tapestry is briskly executed wet-in -wet using various earth colors and natural ultramarine. The blue satin garment, still in the underpainting stage, is modeled with raw umber and white in the highlights. Nowhere in Vermeer’s oeuvre has iconographic interpretation proved so complicated as in The Art of Painting. Experts generally believe that the glittering golden chandelier surmounted by a double-headed eagle, imperial symbol of the Habsburgs, refers to an earlier era when that dynasty ruled the Netherlands. One critic suggested that the eagle may have been an allegorical symbol of sight, one of the five senses meant to strengthen the focus of the painter’s activity. It has also been seen as an image of the phoenix, a symbol of a resurrected and reunited Netherlands. Whatever its iconographical meaning, it is hard to imagine that Vermeer, perhaps the most “optical” artist of the Netherlands, was not attracted by the formidable technical challenge it posed to his eyes and craft.