Posted by Randy (SD) on October 20, 2003 at 09:33:43:
My only experience with ?knock down? is used by professional dry wall contractors. It is a heavy textured material similar to very wet dry wall mud (the stuff used to cover taped seams and nail holes in dry wall installation). It is applied by spraying the material on a ceiling (never saw it used on a wall) and then ?knocking down? the high spots. Hence the name ?knock down?. It is not a do-it yourself application unless you have the experience and skill. Typically used in new construction before the final trim and carpeting are installed. Check with your local paint store or building supply center for clarification.
There is also a type of wall paper that is very thick, plain white with a kind of egg shell texture that is applied just like any wall paper but it conceals blemishes in the surface. You might find it easiest to scrape the photographs and posters off, sand the area by hand and use dry wall mud to apply a skim coat over the effected area and repaint.