Choose and apply images
Thin paper is best for decoupage projects because it will create minimal texture on the item's surface. Wallpaper, gift-wrap, art posters and pages from old books are ideal as they are the right thickness and can provide ready-made designs. Use sharp scissors when cutting out images so the edges are crisp.
Decide where you want the pictures to go. Place them on the item's surface and lightly trace around each one with a pencil.
Remove the paper and spread a thin layer of a decoupage medium such as Mod Podge over the entire item using a foam brush. (A water-based white craft glue will work just as well when mixed with a couple of teaspoons of water.) You'll need to work quickly because the glue must be wet when the images are positioned on the surface.
Place the cut image in the designated area. Use a damp sponge and brayer (a small-handled roller used to smooth out the paper and prevent creases from forming) to get rid of any excess glue, water and air bubbles trapped underneath the paper. Work outward from the centre of the image as you smooth and flatten it. Check it frequently during the first hour to smooth out any air bubbles that may form as the glue dries.
Leave the item for at least one week, allowing the glue to cure completely before applying the varnish.
Finishing touches and tips
Once the sealant has cured, apply three to five coats (one per hour) of acrylic polyurethane (or a decoupage medium specifically designed for outdoor use) over the entire piece with a foam brush. Not only will it seal the paper to the piece and create a smooth surface, it will help protect the item from the elements.
The curing process for this type of finish can be extensive, so try not to put any really heavy items on the piece for at least a year. Even though the surface will feel hard and dry within a day or so, the layers underneath could still be soft. Heavy items, such as concrete planters, can cause dents in the finish (light to moderate objects should be fine).
A piece of decoupage that is placed in direct sunlight will fade over time. Extreme heat can also sometimes cause polyurethane finishes to de-laminate, so try to keep decoupaged items out of direct sunlight when possible.
Like with any outdoor furniture and accessories, continued exposure to the elements will cause pieces to deteriorate over time. Keep decoupaged items under a shelter when possible and put them away during inclement weather whenever you can. The layers of sealers will help protect the item, but taking a little extra care will ensure that your new work of art will last for many years to come.
Lauren Flanagan is a freelance writer and prop stylist in Toronto, specializing in antiques, home décor and travel. Her work has appeared in several Canadian publications including Style at Home, where she was the assistant design editor, and Suite 101.