Cosimo Tura, 'The Virgin Annunciate', probably about 1475-80

Something – or someone – has interrupted the Virgin Mary’s reading. The pages of the small Bible on her knee flap as she moves; she appears to recoil from whatever she can see over her right shoulder. The painting has been cut down on all four sides – Mary’s halo has been cut in half – and was probably part of a large image which included the angel Gabriel, the cause of her surprise.

Gabriel brought her the news that she would conceive a child by the Holy Ghost and that he would be the son of God (Luke 1: 26–38). If you look closely at the upper left-hand part of the picture, you'll see a series of fine lines incised into the panel. These once surrounded the dove of the Holy Ghost, often depicted emanating golden rays.

The Virgin is seated against the backdrop of a hazy wild landscape with rocky precipices on one side and an ordered city with bridges and classical-style buildings on the other. Her elaborate carved wooden seat is as much a feature of the picture as she is; these kinds of chairs were fashionable in the Renaissance. It is transformed into a throne by the addition of a slender backrest and canopy, which is improbably small in relation to her head. To the right is a white marble pilaster, painted to look as though it has been carved with decorative foliage, its dark outlines confidently painted with a fine brush.

Strong dark lines can also be seen through the paint surface, particularly in the Virgin’s hands and neck. This is the design Tura drew onto the panel before he began to paint. He used repeated parallel lines to indicate the shape and volume of forms. Visible underdrawing is characteristic of Tura’s painting, partly because of the slightly rubbed surface of some of the works, but also because there was so much of it. It can also be seen very clearly in his painting of Saint Jerome. His method of outlining features is very recognisable and can sometimes, as here, appear exaggerated and unnatural. This was probably a self-conscious decision, intended to distinguish him from other artists and to highlight his inventiveness. He favoured adding or over-emphasising curves in the outlines of physical features, so the Virgin’s ears and lips here, for example, are made up of several round and crescent shapes; her knuckles seem excessively bony.

The way in which her fingertips but not her palms touch in prayer resembles the work of the Netherlandish painter Rogier van der Weyden – see the gloved hands of the bishop on the right in The Exhumation of Saint Herbert. Tura’s painting technique also reflects that of Rogier, for his skill in using oil paint. Although this is a picture made much later than the finest example of Tura’s oil painting, A Muse (Calliope?), he has used egg tempera with a few areas painted using walnut oil.

This picture has suffered considerable damage, particularly in the Virgin’s face, due to a split in the wood. These areas of loss have been restored by the National Gallery’s conservation team.