Some artists work in oil on canvas, others in charcoal on paper. Jim Denevan prefers sand on beach. If you’re ever fortunate enough to see a Denevan original, take it in while you can, because waves will soon wash it away. “Sand drawing is the ultimate waste of time,” he says without disparagement in the short film Jim’s Lines, which you can see on YouTube. The Santa Cruz, California, artist uses sticks and rakes to create contrasting patterns and images such as this nautilus-like form at Ocean Beach in San Francisco in 2006. A recent Denevan sand work on a dry Nevada lake bed displayed extraordinary longevity, according to OnEarth (Summer 2009): Three miles in diameter, it lasted a week before a rainstorm washed it away. See more of his art at www.jimdenevan.com .