Starting with blue and green stripes on a white field, I drew 21 circles of various colors. The circles slowly expanded without touching any existing lines!
The main challenge for this type of piece is keeping the background lines shaped like circles! I drew everything freehand using markers, so there are no erasures and there is no undo button!
The permalink for this piece is http://art.robnugen.com/21
Colorful lines look like they overlap, but actually do not!