What is Nap?

Nap refers to the thickness of the fabric pile on a paint roller cover, measured in fractions of an inch. Smooth surfaces like drywall call for a short nap (3/16" to 1/4") that delivers a fine finish without texture. Rough surfaces like stucco, brick, or popcorn ceilings require a thicker nap (3/4" to 1-1/4") to carry enough paint into the surface irregularities. Choosing the correct nap is essential for achieving even coverage and the right final texture.