Once the rudiments of a composition had been established, an artist could then draw from a model as part of the further planning, as for example, Van Dyck’s Studies of a Man’s Forearms. They are careful, detailed and subtle: the tonal modulation expertly done, the choice of blue paper permitting the application of white chalk highlights for volume – all the information needed to paint. The other side of this sheet shows A Child at his Mother’s Knee, part of the initial preparation for a portrait. It is a quick sketch of a young boy, who rests his hands on his mother’s lap. The drawing captures, with quick, brusque lines, the child’s attachment to his mother, his intrigued, outward gaze, and enough detail of form and costume to enable the painter to proceed.[1]