Katharine Hepburn, Calvin & Hobbes, Mother Teresa and more -- 2010 US postal stamps

These stamps honor the artistic innovations and achievements of 10 abstract expressionists, a group of artists who revolutionized art during the 1940s and 1950s and moved the U.S. to the forefront of the international art scene for the first time. Abstract expressionism refers to a large body of work that comprised radically different styles, from still, luminescent fields of color to vigorous, almost violent, slashes of paint. The stamps go on sale March 11.