Employing dots of different sizes creates the illusion of near and far on (in) the paper: the large dots read as near points and the small dots as points that are farther away. Use this effect to create three dimensional relationshipds among the points much as you created interesting two dimensional patterns among same-size dots in the previous excercise.
Another variable is permitted. The dots may be of two types: filled or empty. filled dots are what you have been making so far. empty ones are simply ink-drawn circles. The consequence of this variable is to provide you with two different kinds of dots so that you may create additional complexity. In the viewer's eyes, empty dots tend to relate to other empty dots, and filled dots connect stronger to other filled dots. Rhythms and sequences of combinations of filled and empty dots may be created.