Exterior stains for clapboard and cedar-shake siding come in solid and semitransparent formulations. Opaque (solid-color) finishes look almost paintlike, covering the wood completely so the grain doesn't show. Semitransparent stains add color to the wood but let the grain show. Either type soaks into the wood, leaving a flat dull, finish.

WHAT'S AVAILABLE

The major brands include Ace, Behr (sold at Home Depot), Benjamin Moore, Cabot, Olympic, Sherwin Williams, True Value, and Valspar.

Stains come in a fairly limited range of basic colors: reds, greens, blues, grays, browns, and whites. Whether solid or semitransparent, stains come in water-based and oil-based formulations.

Price range: about $20 to $30 per gallon.

HOW TO CHOOSE

Pick opaque. We have found that top-rated opaque stains offer the most protection and can last about nine years. Semitransparent stains, which let some wood grain show, aren't as durable.

As a rule, water-based latex stains are easier to work with than oil-based alkyd stains because they clean up with water.

Consider where you live. Stains of any color accumulate dirt over time. The top-rated stains tended to resist it better than the others; darker colors hide it better.

Mildew can be a problem in damp areas, from rainy Seattle to steamy Tampa, or on any house that gets more shade than sun.

Baking in bright sun can change even the best-quality pigments. Blues are the most likely to change.

Don't overlook the prep work. Be sure you sand and clean the siding thoroughly before applying the stain. Good preparation makes any stain last longer. And plan to apply two coats.