When you purchase paint, you do so sight unseen--and there is no way of knowing how good a paint is simply by examining the can. But Consumer Reports can help, with our tests of interior latex paint, kitchen-and-bathroom paint, deck treatments, and exterior paints and stains.

For interior latex paints, we judge "hiding power" (opacity), flow and leveling (how smooth the paint looks when applied), mar resistance (the ability to resist change when paint is scratched or rubbed against), and touch-up performance (the difference in gloss and color between paints applied with a brush and those applied with a roller). Our hiding chart (below right) consists of a 3x6-foot paper panel divided into three sections; each section contains six stripes ranging from pale gray to black. The point at which the stripe underneath is no longer visible is the point at which we note a paint's hiding power. We look at both one- and two-coat hiding, and have found that some paints are as good with one coat as others are with two. We also assess how easy the paint is to clean, how tough it is, and how water resistant it is.

In our tests of deck stains, we look at dirt accumulation, mildew resistance, sun damage, and cracking. Mildew-resistance tests are conducted on white pine panels (below left) that are exposed outdoors, in a shady location facing due north in a vertical orientation that most favors mildew growth. Here, exposed panels have been placed over retain panels that haven't been exposed. As a whole, clear products have proved very disappointing.