The Hillstrom Museum of Art at Gustavus is hosting two new exhibitions until Friday, Jan. 30. Illusion and Certainty will be on display concurrently with Come On!: American Posters from World War I. Illusion and Certainty includes 50 paintings by New York artist Martin Weinstein and Come On!: American Posters from World War I consists of 33 propaganda posters from the World War I era, on loan from the College archives.