Op Art Snakes

Can lines create three-dimensional optical effects? Here is a new example with three snakes trying to camouflage themselves between the lines … With students of the sixth grade we experienced the 3D effect created only through parallel lines. Before we drew the snakes with pencil and then we filled the sheet of horizontal lines with a sequence of four colors felt-tip pen. Whenever our line “meets” the serpent, we must draw a “bump”, trying to keep the lines parallel.
Materials:
1. drawing paper
2. pencil
3. colored felt pens
The activity takes 1 hour