Oil paintings can last many for many generations, but only if they're carefully preserved. You must take special care to protect oil paintings from dust, scratches, humidity and other harmful factors. Here's how to protect an oil painting.
Coat the surface of the painting with a layer of varnish to preserve it. This should only be done by the artist after the painting has thoroughly dried (about one year on average), or with the assistance of a knowledgeable conservator.
Hang oil paintings in places where they will not be knocked over or scratched. Make sure there is no possibility of water dripping onto it. Avoid placing oil paintings near windows, fireplaces, radiators, heaters .
Remove dust from the surface of an oil painting with a soft brush (goat hair brushes from the craft store work well) or a pure white cloth. Don't use feather dusters or sheepskin dusters, which can catch on the surface texture of the paint and damage the painting.
Protect your oil paintings while moving. During the move, place them in a safe location, such as a closet, where they won't be bumped. You also can move them into your new home first. When your paintings aren't hanging, rest them, painted side out, against a wall with a padded surface beneath them. Do not cover paintings with plastic no matter where you store them. They need air circulation to prevent moisture buildup.
Never place oil paintings in the kitchen or bathroom. The changing levels of humidity will cause damage including mold and/or mildew. Do not allow people to smoke in rooms where valuable paintings are kept.
Wash your hands whenever handling an oil painting; oils from your hands can damage the surface.