You’ll need: black cardstock or mat board, oil pastels, a bar or piece of soap (small enough to draw with), & and wet sponge or paper towel.
1
Use the edge of the soap to draw a design. Make your lines nice and thick.
2
Use oil pastels to color inside, outside, and between the soap lines. Try to fill the whole page with color so there’s no black showing.
3
Wet a sponge or paper towel with water, then wipe off the soap lines.
The video below contains extended project instructions
Example Soap and Oil Pastel Drawings from the Arts For Life archive created by (clockwise from top left): Cheo, Carlie, Tasha, & Katelyn.