Nine Ways to Make Your DIY Paint Job Look Professional

Paint is the cheapest, easiest renovation you can do: it makes everything fresh and new, it covers defects, and it’s something almost anyone can do to a reasonable level of quality.

If you just read that last part and started shaking your head because your paint projects always turn out terribly—patchy, or with visible sheen or brush strokes, or a final color that doesn’t seem to match what you chose in the store at all—the cause probably isn’t your work ethic, or an evil spirit inhabiting your house. The problem probably lies in your prep work. If all you’re doing before you start slapping paint on the walls is applying some painter’s tape and covering the furniture, the chances that the final paint job will look terrible are actually pretty high. Here are all the things you should take into account before you dip that brush.

Consider temperature and humidity

The weather can affect the quality of your paint job. Extreme temperature or humidity can have an adverse impact on the drying time. At colder temperatures, paint can thicken, extending its drying time. At hotter temperatures, it can dry too quickly, affecting adhesion. High humidity that leaves moisture on the walls will also result in a sub-par paint job.

Your home is probably climate controlled, so painting inside even during extreme weather is certainly possible—just make sure the temperature is between 50 and 90 degrees and the humidity levels are between 40 and 60%.

Prep the walls

It’s usually a good idea to wash your walls before painting them to ensure there is no dust or dirt that could adversely affect adhesion. While you’re at it, look for cracks, dents, peeling tape, or other defects and patch everything up (including crayon or grease stains that will probably show through your paint unless they’re scrubbed off). A small flaw that isn’t noticeable now might become a glaring problem when a fresh coat of paint brings it to the forefront.

Cleaning walls with a dry microfiber cloth followed by warm water and a sponge is usually sufficient, unless your walls are really dirty. If you’re worried about it, add a small amount of dish washing liquid or trisodium phosphate (if your walls are greasy and very dirty)—but avoid colored soaps that might leave a tint behind.

Choose the right rollers

One big reason paint jobs look like crap? The nap on your roller cover. The nap of your roller describes the thickness of the fibers. Generally speaking, the smoother your wall surface is, the smaller the nap of your roller cover should be. Painting kitchen cabinets? Go with a 1/4-inch nap. Painting a brick wall? An inch or even a 1 1/4-inch nap is best. Smaller fibers pick up less paint, while thicker fibers hold more paint—a too-short nap can result in a patchy finish on rough surfaces, while a too-long nap can add unwanted texture to smooth surfaces. Most interior paint jobs will call for a nap between 3/8 inch (very smooth walls) and 3/4 inch (textured walls, like stucco).

Apply a separate primer coat

These days you can buy paint and primer together, which is a terrific time saver. But if your walls aren’t in great shape, even after cleaning and patching, you will usually get a much better result with a separate primer coat. This step might not be 100% necessary on your walls, but taking the extra time to prime properly will guarantee the best possible outcome.

Identify the paint's undertones

Almost all paint has an undertone (its base color )and a masstone (its overall hue). The undertone can be subtle and difficult to suss out, which is why it’s so important to paint a few samples on the wall before you commit. The paint’s undertone will interact with everything else in the room in ways that aren’t always obvious in the store. You brought home a beige paint, for example, but it has a green undertone, and suddenly it looks all wrong on your walls because your wood floors have yellow undertones.

You can ask about the paint’s undertone at the store where you’re buying it. You can also use a color wheel to compare it to primary colors to get a sense of the undertones involved.

Combine multiple buckets of paint

If you’re painting a small room and using just one can of paint, you’re good to go. If your project is larger and you’ll be using multiple cans of the same color, you should combine all your paint into a larger bucket and mix it up—a process called “boxing.” This is a good idea because even if you bought your paint from the same store at the same time, there can be subtle variations between cans. Maybe the pigments dispersed incorrectly, or the mixing process was slightly off. Whatever the reason, even the tiniest variation between cans will be incredibly obvious when you switch to the new can. Boxing it eliminates the danger.

Check out your window tint

Your windows can throw a wrench into your paint colors. This is because many windows have a very subtle green tint due to the presence of iron oxide in the glass. This isn’t noticeable in any way to the naked eye, as a rule, but it can cast a greenish tint on your paint that’s just strong enough to make it look inexplicably wrong in the daylight. Putting samples on the wall to judge the color is a great idea—but make sure you paint those samples in a spot where the light from your windows will hit them. Samples that look perfect in a more shadowed area may suddenly look weird when light hits it through the window.

Figure out the color temperature of your lights

Another lighting issue is your light bulbs. All the bulbs you’re using in your light fixtures have a color temperature, and that can affect how your paint looks. Generally speaking, bulbs with higher color temperatures will brighten darker paint and mute lighter colors and vice versa. This means that a paint color that looks terrific in daylight can suddenly look grim or faded at night when the lights come on. It’s best to check your samples in all kinds of light to make sure you’ve chosen wisely—and change your bulbs to support your paint if necessary.

You should also check the color rendering index (CRI) of your bulbs. This is a rating between 50 and 100 that indicates how accurate the color rendering of the bulb will be. A CRI of 90 to 100 will show your paint as accurately as possible, reducing the chances that it will look worse when the sun goes down.

Load your roller up

Finally, when actually painting, don’t be shy with your roller. When initially “loading” paint onto a dry cover, take your time and work paint deep into the nap. This can take a few minutes, so don’t rush—you want a nice, wet roller when you hit the wall. When painting, don’t roll until the roller is exhausted—reload frequently and keep the nap damp. Exhausting your roller will just leave streaks and faint spots that may or may not get covered by a second coat—and may or may not haunt you for years afterward.