The Wooster 18" Painter's Solution. A 3/4" nap roller cover sounds like a professional-grade equipment for painting work. With a 3/4" nap, it's most likely intended for painting semi-smooth to semi-rough surfaces, providing adequate coverage and a smooth finish. Wooster is recognized for making high-quality painting tools, so you can count on this roller cover to be long-lasting and functional for your painting needs.