Read this before you buy new paint. Consumer Reports just tested gallons of it to find the best for your buck

Whether you are trying to spruce up your home for yourself or potential buyers, a new coat of paint could be just what you need. But a new round of Consumer Reports tests reveal — if you’re shopping by brand name alone, you’re probably not getting the best paint for the job.

“Since we test so many paints and so many different types of paints, we spend about twenty hours, about a week’s worth of work to just prep,” said Lilly Carrera with Consumer Reports. “We actually have to prep all the paint boards; we have to cut them to size and then we have to mark them off.”

When the samples are ready, testers run exterior paints through a mildew resistance test. And of course, weathering — to see how well it stands up to the elements after years of exposure. The samples are then left on Consumer Reports’ roof for three years, which simulates nine years on a home. They are tilted south to amplify the sun’s effects, then inspected for cracking, dirt collecting, and fading every year.

(Check out the behind-the-scenes footage at the bottom of this article to see how paint is tested)

Test results

If you’re planning an outdoor paint project, Consumer Reports recommends two:

1. Behr Ultra Exterior (Home Depot for $52 per gallon)

2. Clark + Kensington Exterior (Ace for $47 per gallon)

For staining, Consumer Reports’ top-rated Behr Premium Solid Color Waterproofing Stain & Sealer (from Home Depot for $50 per gallon) resists fading, cracking, dirt, and mildew. Plus, it holds up even after three years in Consumer Reports’ weathering tests.

For interior paints, testers look at how well each one can cover and resist oil and water-based stains. And, as any DIY painter knows, covering a dark color can be very difficult, so Consumer Reports’ tests show how easy — or hard — that is with any given paint.

“Once it dries, we compare how well it hides the black to the white,” Carrera said.

Testers found, if you’re looking to freshen up a room inside your home, these two provide excellent coverage and stain resistance:

• Behr Marquee (from Home Depot for $53 per gallon)

• HGTV Home by Sherwin Williams Showcase (available at Lowes for $52 per gallon)

Pro-tip for all paints and stains: Don’t shop by brand name alone.

“I would say that’s not a good idea because the same brand can have different formulas and they can vary per test on how well they do,” Carrera explained.

If you’re tackling a bigger job that involves more than three gallons of paint, Consumer Reports says you may want to consider a paint sprayer. A handheld sprayer can also come in handy for projects with hard-to-reach angles and nooks and crannies like on furniture or staircases.

Behind-the-scenes footage from Consumer Reports’ paint labs

WATCH: Exterior paint testing

WATCH: Interior paint testing

WATCH: Mildew resistance test