Care of Decoupage
Not many speak of the care of decoupage but it is necessary to keep your piece beautiful. A piece that has been waxed (as all mine are) should be waxed periodically, maybe once a year. Just as you would with any other fine furniture wipe all spills immediately with a soft cloth. Do not use furniture polish, these can cause a buildup and over time will ruin the surface. A damp sponge or cloth works well.
Do not place a piece of decoupage in direct sunlight, it will fade over time.
Varnish takes about a year to fully cure. Do not sit heavy objects on a flat decoupaged surface for at least a year, it will cause dents in the surface. After a year has passed the varnish has hardened and you are home free. Varnish dries from the top down, so it may feel hard and dry on the surface but deep down the finish is soft.
Over time you will see dings and chips, but these can be repaired and should. If the varnish is chipped but the decoupage has no damage, sand the surface around the ding with No. 600 wet dry sandpaper, then with #400 steel wool. With a small brush apply a drop of varnish and let dry. Repeat until the chip is filled. Sand with a rough sandpaper, then medium, then the No. 600 and finally #400 steel wool. Wax it again to match the surface.
Decoupage is not hard to care for and with proper care it will last for centuries.