How much prep work for painting interior walls?
Re: sanding — Depends on what you intend to do to the walls after painting. I’ve only ever sanded down the putty to smooth it before painting. We put some wall stickers up for a while and the paint lifted when the stickers were removed, indicating the latex hadn’t bonded very strongly between new and old layers (i bet the sanding is for improving adhesion between layers). Same with getting my clawfoot tub refinished in my bathroom – the painter’s tape lifted the bright blue paint from the formerly white walls. Lesson learned: keep some touch-up paint on hand.
