If the ceiling is perfectly even, then you can do with good, high -quality wallpaper, at the request of the owner himself. They hide the flaws of the ceiling, curvature, small casting cracks. The main minus of the wallpaper is that it is difficult to wash or wipe them, but in general it is not a bad option for a cosmetic and not expensive repair. And if you decide to make repairs again, then this wallpaper should not be changed, if they look sad, you can give them a second life with a special paint!