On Alberti's "sign": vision and composition in quattrocento painting - Leon Battista Alberti's commentary 'On Painting'

Like most Renaissance paintings, Gentile da Fabriano's Adoration of the Magi [ILLUSTRATION FOR FIGURE 7 OMITTED] embodies what it represents. With the exception of the golden haloes and background, all the shapes and colors within the pictorial field may be read, from moderate viewing distances, as optical signs for depicted persons, animals, and objects. Although the liberal use of gold advertises the preciousness of the crafted image, much of the gold is used for representing golden things and hence makes visible the materiality of depicted objects.(149) As in medieval art, gold is valued for its splendorous luminosity, but here its luminosity is associated with the illumination of the scene as well as with reflected light.

Gentile pushes the correspondence of local color with material to a new level. In some places, shadowed surfaces are rendered with saturated local color, and white is added to "up-model" the illuminated ones. Down-modeling through the addition of black is used only for the few cast shadows, such as that on the city wall in the right lunette. More often, Gentile found ways of modeling by varying tone without adulterating hue. In some places, the density or quality of pigment is altered so that the white ground shines through or the local color has greater brilliance in brightly illuminated areas. Elsewhere he employs what Hills terms an "elementary pointillisme," the distribution of tiny dots or flecks of dark or light over the local color.(150) A few passages are modeled by sgraffito, the scratching of an overlaid color so that an underpainted color shows through. These techniques are carried out so minutely that from moderate viewing distances the optical mix is more or less complete.

Both the direction of illumination and the way in which light is rendered changes from section to section.(151) Light falls from the right in the left and central lunettes and from the laminated gold guiding stars in the right lunette and the main scene. Objects near the guiding stars glow with golden light: gold leaf, applied with painted adhesive in a "mission" technique, highlights foliage; yellow glaze and mission gold dots model the cloak of the maiden at the Virgin's side; sgraffito exposure of gold underpainting illumines the hills of Bethlehem in the right lunette and the cave mouth and some garments in the main scene;(152) and yellow pigment added to local color renders the golden light bathing the walls of Bethlehem. Since the brocaded mantle of the kneeling king, the blond hair of Jesus and of the handmaiden behind Mary, and the overhang of the shed are glazed over with silver, they, too, must have glowed when the painting was still fresh. Bright yellow highlights on the foliage below Jerusalem suggest the diffusion of starlight into the central lunette, and the use of mission and mordant gold on so many objects, garments, and ornaments strengthens the sense that golden starlight permeates the whole.

The textures of depicted objects are rendered through an impressive array of craft techniques.(153) In some places, Gentile engraved the warp and weave of fabric into the surface of the paint. Designs of embossed, brocaded, and embroidered garments are punched, punted, and tooled into the picture plane. The crowns of the three kings, the spurs of the youngest king and his page, the hilt of this king's sword, the tip of its scabbard, and the collar of the reclining greyhound are built up with pastiglia. This textural correspondence between paint and depicted things extends to the gold regalia, harnesses, sashes, palliums, and so forth. These items are aligned with the picture plane so that the patterns worked into the gold leaf mimic the decorative designs on the depicted objects themselves.