Students in grades 4-5 love this easy, but impressive op art project, and it’s a great way to illustrate the element of art, “Line.”
I start by having students trace their hands very lightly with pencil, then make a horizontal line pattern in the background. I tell them to be sure to end the horizontal lines right at the outline. Then, I tell them to create a contour (curved) line pattern on the hand, itself. The change in line direction gives the illusion of a 3-D hand.
The more close and precise the lines, the better the 3-d illusion. Also, it’s best not to use a really light color.
Not all drawings work out, but most students get the concept, and many try experimenting with other shapes and line patterns on their own, later.