Silly sandwich- (Note: great art project when teaching about texture)
Pen and Ink Illustration of a Canal. Venice, Italy.
JR Sketches: Luberon, France 2013 1 - Set 2013
several hatchings such as cross lines and dots are used to represent the depth within this portrait. as seen in this image the darkness of an area is shown by doing a much more of a closer/tight hatchings.