A repair in a plaster ceiling or wall should be invisible. No one should be able to notice the repair after the final finish of paint, texture, or wallpaper is applied. And this should hold true for 20 or 30 years afterwards. That's the goal. All too often, however, a splendid renovation is spoiled shortly after completion when hairline cracks return, or a fissure opens up where new work joins the old. Hairline cracks in old plaster require more than the painter forcing in some spackling paste and sanding until smooth. And joining new drywall to existing plaster requires more than taping with gypsum-based joint compounds. In this article I'll describe the basic techniques I use to repair old plaster and patch in new work. I won't treat ornamental plaster,
