ABSTRACT
In chapter 1, I stressed the importance of distinguishing between the marks in children’s drawings and the picture primitives that these marks stand for. Picture primitives, the units in pictures that carry meaning, are represented in pictures by physical marks such as lines of ink or pencil, blobs of paint, or the lines of stitches in a sampler. Except in unusual circumstances, however (as when we view an Impressionist painting from up close), we do not normally pay attention to the marks but see through them to the picture primitives for which they stand. In much the same way we rarely pay attention to the actual sounds people are making when they speak because we only listen to their meanings. The dimensions of the marks used in pictures may in practice be different from the dimensions of the primitives they represent. For example, the one-dimensional lines in a picture may be realized physically using small pieces of mosaic or knots of wool-marks that are, in themselves, zero-dimensional. Conversely, marks in the form of one-dimensional lines in a picture may be used in hatching to represent zerodimensional optical features, such as the continuously varying tones in the cross-sections of the light rays coming from areas of tonal modeling or cast shadow. Sometimes the picture primitives represented may not be present
at all but are only implied by marks. In the 18th-century silhouette shown in Fig. 6.22, for example, the marks are areas of paint but the meaning of the picture lies in the shapes of the lines enclosing these areas, even though there are no lines that are physically present.
