Nathun Finkhouse of Mosaic Arts Alliance will offer “Weathered Boards and Rusted Tin: Painting Barns in Watercolor,” from 9 to 11 a.m. May 20 at Clark College Frost Art Center, Room 103, 1933 Fort Vancouver Way, Vancouver. The focus will be on earthy color mixing, using various texture combinations, and emphasizing the imperfections in the scene. Students should bring their own photo references or choose a photo from Finkhouse’s collection. The cost is $70 per person. Register at mosaicartsalliance.org/event-details/weathered-boards-and-rusted-tin-painting-barns-in-watercolor-with-nathun-finkhouse.