Most residential repaint calls trace back to one cause: wrong roller spec for the surface. Wrong nap on smooth drywall creates stipple texture that appears in every finish coat. Wrong nap on textured walls leaves unpainted voids. Neither is a paint quality failure. Both trace back to a specification decision made before the first stroke. Nap thickness, cover material, frame construction, and the wall-versus-ceiling difference each get their own section. The distributor stocking section covers which SKUs move fastest in professional accounts — and why the consumable consistently outsells the