In some regions, a textured wall is expected (we’re thinking of adobe-style houses both new and old in the Southwest). That’s great, but if your walls and ceilings are pocked and marked in a land of sheetrock, it might deter buyers who want a less specific look. To mute the texture, paint the walls with a matte or eggshell finish. Gloss just draws attention to the topography. If it’s in your budget, sand the walls down to be rid of the finish altogether.