This technique is similar to disappearing ink. A young artist from Seattle Peregrine Charch learned to draw on the asphalt with invisible inks, which appear only after the rain. A series of drawings in his hometown called “Rainworks”. City officials, of course, such an art, because the drawings are non-toxic and are not harmful to health. The pictures “live” from a week to a year, depending on how many people per day walk on it.