The Wooster 9" Painter's Solution 3/16" Nap Roller Cover is a special type of roller cover used for painting. The "9 inch" refers to the breadth of the roller cover, indicating that it is suitable for usage on wider surface areas. The "3/16 inch nap" label denotes the thickness of the fibers on the roller cover's surface.
A 3/16-inch nap is considered medium thickness, making it appropriate for smooth to semi-smooth surfaces. It strikes a compromise between holding enough paint for adequate coverage and evenly distributing it on the surface. This style of roller cover is often used for painting walls, ceilings, and other interior surfaces that require a smooth finish.