A horizon line is one that helps artists establish space and dimension in their pictures. Young artists use pastels (chalks) to draw landscapes that use a horizon line. They draw the image with black chalk fist, color it in, and finally add details. Note: It may be better to have the kids use pencil to outline, then have them color, and then use the black chalk last. Black chalk tends to get everywhere and is more difficult to cover up than lighter colors.