Related Clues:

• Sistine Chapel painting, e.g.
• Many a commissioned artwork
• Wall art
• Rivera work
• Art on plaster
• Plaster art
• Hard-to-move painting
• Lengthy painting
• Community art project, maybe
• ''The Last Judgment,'' e.g.
• Wall painting
• Work by Chagall
• Subway artwork, perhaps
• Fresco, e.g.
• Painting on moist plaster