A wooden drawing board from ancient Egypt with a figure of Thutmose III, preserved in the British Museum (EA 5601), documents how Egyptian artists used various media for practicing or creating their designs.
"The most common [surviving examples] are ostraka (flakes of stone or potsherds used as drawing or writing pads), but several wooden drawing boards have survived. The surface was coated with gesso and then smoothed; it could then be cleaned and reused. The figure of Thutmose III on this board was perhaps a preliminary drawing that was later to be transferred to a tomb or temple wall, while the other drawings were presumably practice hieroglyphs.
"This object is significant because the design has been laid out on a grid. From the Old Kingdom (about 2613-2160 BC) onwards, a system of guidelines, later developed into a squared grid, was used to ensure the correct proportions of the figures. Before the Late Period, standing figures were generally laid out on a vertical grid of eighteen squares measured to the figure's hairline, and seated figures on one of fourteen. The horizontal lap of the seated figure accounts for the missing four squares. Grids were drawn onto the walls and even onto the stone of statues. When the scene was finished the lines were either cut away or painted out. Hence unfinished walls and practice sketches where the grid remains intact, like this one, are of immense value" (http://www.britishmuseum.org/explore/highlights/highlight_objects/aes/w/wooden_drawing_board_with_a_fi.aspx, accessed 07-11-2009).