The document discusses various techniques used in two-dimensional artwork to suggest depth and space, including placement and size of objects, overlapping, changes in detail and contrast with distance. Objects higher on the picture plane or larger in size appear closer. Overlapping and clearer details with higher contrasts also make objects seem nearer. More distant objects have softer edges and details with less contrast creating an illusion of atmospheric perspective and receding space. These principles are demonstrated in examples from Thiebaud, Seurat, da Vinci and others.