Know Your Nap
Every paint roller cover has a nap length. You'll find it listed on the packaging. This is the length of the fibers that are attached to the roller core. We use longer naps for rougher surfaces because they can get deep down into the nooks and crannies. They also hold a lot of paint. Shorter nap paint roller covers are used for smoother surfaces. They leave less textured bumps on the surface resulting in a smoother finish. The downside... but they hold less paint so you'll have to go back and forth between the paint tray and your paint project more often.
Here's some of the more popular nap lengths you’ll need to know:
3/4″ to 1 1/2″ Nap (Heavily Textured Surfaces)
For the bumpy and rough surfaces: deep grooves like mortar joints, brick, and troweled stucco you need a heavy nap. Don't use these long naps on a smooth surface because it'll leave a rough texture, but on rough surfaces you need those fibers to really get down deep into the crevices. These nap sizes hold a lot of paint so be prepared for a potentially messy application if you aren't careful.
1/2″ Nap (Light to Medium Textured Surfaces)
For plaster or textured drywall: This size carries enough paint to prevent too much back and forth between the paint pan and the wall and it's fibers are long enough to get into the small crevices that are common on plaster walls and knockdown drywall finishes.
3/8″ Nap (Lightly Textured to Smooth Surfaces)
For smooth plaster and drywall or light orange peel texture: The 3/8″ nap wins here. It provides great coverage and leaves very little roller marks on your walls as long as you don't try to push too hard on the roller as you apply.
3/16″ to 1/4″ Nap (Smooth Surfaces & Fine Finish)
For even smoother surfaces: These ultra fine paint rollers are usually used for cabinets, trim, doors, and other fine finishes. You'll find these more often in the mini size. Applied with patience, this nap can resemble a spray finish.
As always, quality matters. We use Purdy brand brushes and roller covers for the best in painting materials.