Notional Space

Notional space is the vertical and horizontal space (enclosure) around a particular element in a composition. Determining the notional space allows the artist to measure and plot that particular element on a grid as well as create relationships between other parts in the overall design.

For example, a single figure such as the Venus, we may construct a cube to plot the elements for the composition.

This cube is called a Cartesian Grid.  We can plot all points in the grid along varying axis. 

For more complex compositions, we may use multiple cubes or grids to form an architecture.  This is extremely important when composing from above.