Q. Ive been asked to paint a mural in a private home. The space (24 feet wide, 13 inches tall) is above some windows and a door, with wood molding on the top and bottom. The wall is painted drywall. What do I need to do to prepare the surface for painting? Would it be better to use acrylics rather than oils? Or should I just fit canvas or canvas boards between the moldings?
A. When Im commissioned to paint a mural, I offer two options: painting on the wall surface directly or on a piece of stretched canvas or Masonite sheeting (which I would then have installed). I charge 20 to 25 percent less for murals done right on the wall surface. The downside to this approach is that the clients cant take the painting with them if they move.
If your client would prefer a removable mural, I recommend Velcro strips as an easy way to attach the canvas or board to the wall. If, instead, youre going to paint directly on the wall (as most of my clients prefer), make sure the surface is in sound structural shape and free of any dirt, grease, wax or anything else that might keep your paint from adhering properly. If the wall is heavily soiled, you can buy specialty cleaners or primers to prep it. The medium you use is a matter of preference; both oil and water-based paints work well. I usually paint murals with acrylics, using an extender to prolong the drying time if I need to. I dilute the paint with water to create thin, layered washes for most of the work.
However, if the wall surface has been covered with oil-based paint, ordinary acrylics wont work on top of it. Watermedia wont adhere to oil-based paints, unless theyre formulated for that purpose (ask your art supplier for recommendations). You can test the walls surface by wiping on rubbing alcohol. If the paint gums up, its water-based. If it stays firm, the walls been painted with oil.
It isnt necessary to seal most murals. But you may choose to add a clear protective coating if its in a kitchen, bathroom or high-traffic area.