How Long Does Leftover Paint Last?
Here are some telltale signs that your paint is past its prime
It’s always a good idea to save some leftover paint, whether it’s for touch-ups or a small paint project. But if you don’t store it properly, years later—when hallway walls, exterior doors, or window casings need a little TLC—you might find that it has deteriorated beyond the point of being able to use it.
Consumer Reports tests water-based latex paints, the most popular type. They’re easy to apply and easy to clean compared with oil-based paints. See how almost two dozen lines of paint perform in our interior paint ratings.
Leftover latex paint can last years, even a decade, or go bad in mere months. “When the paint can is bulging or the lid is puffed up, you know it’s bad,” says Enrique de Paz, who oversees Consumer Reports’ paint tests. “It means microorganisms are eating the paint and giving off gas, which generates pressure and inflates the can.”
How We Test Interior Paints
Using nontinted base paints (before color is added), we evaluate how well each covers dark colors and resists stains. The results show whether the paint provides even and thorough coverage and can stand up to wear and tear.
What to Look for With Old Cans of Paint
In addition to a puffed-up lid or bulging can, signs that paint is past its prime include a thick, rubberlike film topping it, or paint that doesn’t mix well when stirred or doesn’t stay uniformly blended for 10 to 15 minutes after mixing.
Even if your paint seems okay, it’s a good idea to try it out on a piece of cardboard. You want to make sure that it can still be applied easily with a brush or roller, that the color is uniform, and that the surface is smooth and free of visible particles.
“Once you’re ready to paint, use a brush or roller to blend the paint into what’s already on the surface,” de Paz says. “You want to go beyond the spot you’re touching up.” If the touched-up spot is noticeable when dry, try again. The last resort is to repaint the entire area.
What to Do With Leftover Paint
If it’s good, save it. The best way to preserve latex paint is to store it in an airtight container to keep the water in it from evaporating and to prevent microorganisms from getting in. You can keep it in the original can or transfer the paint to a clean jar with a screw-on lid. Keep it at room temperature. That means don’t store it in a garage or shed, where temperature extremes can ruin the paint. Label leftover paint—“Kids’ bedroom walls, April 2022”—so that years from now you’ll know where you used it.
If it’s bad, dispose of it. It’s important to properly dispose of unsalvageable old paint. To find out what to do where you live, check the website of your municipal or county government, or call your local department of public works. Go to Earth911 for more details on the disposal of leftover paint.
And if you just tossed your leftover paint and need to buy more, we’ve highlighted a few of our top picks, listed here in alphabetical order. You’ll notice a couple of them have Greenguard Gold certification, meaning they emit lower levels of volatile organic compounds, or VOCs—particularly formaldehyde—than the industry standard. VOCs are chemicals that can easily become airborne and affect your health, according to the Environmental Protection Agency. Low levels of VOCs—some paints even come with a “zero VOCs” claim—are ideal for interior paint projects.