Découpage is a type of collage that is applied to a three-dimensional surface as a method of decorating the object. It is applied by brushing a paste onto the front and back of the images and positioning them on the object. Découpage is then coated again with the paste. It is not necessary to purchase purpose-made découpage paste. The paste can be made from ingredients you already have in your home.
Making découpage paste at home is simple enough for even older children to do on their own. Simply combine three parts white school glue with one part warm water and stir with a stir stick or shake in a closed, airtight container. Apply this paste to the front and back of pictures with a stiff brush, and position them on the surface of the object. Allow the project to dry to the touch, and apply a coat of paste over the top.
Découpage paste dries as the water in the paste evaporates. You can slow this process down by using glycerine instead of water in the paste. Mixing three parts white glue to one part glycerine will allow you to apply the images to the surface and reposition them for up to an hour before the paste dries. This is useful when the images must make a specific pattern, or the artistic aspects of the découpage are especially important.
Découpage is paper coated in water-soluble paste. Commercial pastes may include a sealant, but many still require an extra coating of some type of sealant to ensure the découpage isn't damaged during use. All objects made with homemade découpage paste should receive a layer of sealant. Spray-on acrylic craft glaze or several layers of varnish work well for sealing découpage. Wait until the paste is completely dry before applying any type of sealant.
Store your découpage paste just as you would any glue. A canning jar makes a perfect airtight container, but it can be stored in an old glue bottle or any other type of cup or container that seals out all air. Because the paste is water-based, it will dry out eventually if it is exposed to air.