Possible Clues:

• Cloth for painting on
• Tote bag material
• An artist paints on it
• Endless campaign sails close to the wind
• Coarse cloth for sails, tents etc
• Boxing surface
• Painter's backdrop
• Do not begin to examine most of huge painting
• Intent, say, on being under it
• John Trumbull's 'Declaration of Independence,' e.g.