Tips and things to know from apparaiser Karen Keane:
Faded is Fine for Painted Wood - Collectors of antique furniture want their pieces to remain as close as possible to how they were originally, which often included a coat of paint. Over time, paint oxidizes. This fades the paint and gives it a mellow look. Even if the paint dries to the point that it begins to crack, it's better left alone. A little bit of craquelure is absolutely acceptable and gives you a feeling of comfort that it's original. Resist the temptation to "freshen" up a finish with lacquer over original paint - it is not a look that painted furniture collectors like to see.
Avoid Oils on Stained Wood - Oil is very bad for wood. It soaks into open grain and oxidizes and can turn the wood black. The one addition to stained wood is acceptable is wax. Wax creates a protective surface on the piece and is easy to remove, a feature that all furniture conservators appreciate. Solid waxes, such as paste wax, butcher's wax or even French polish are recommended because these all contain bees' wax.
Check out the entire article right here at the Antiques Roadshow site for more info from Karen Keane on finishes and value.
Photos: Antiques Roadshow