First of all, thank you all - I have looked so long for a place to find information and to ask questions, and this is the best there is...Please - two questions: I just cant seem to find a definitive answer with re to applying any natural finish, e.g. venetian plaster, limewash, etc, over modern "plastic" paints. I know that the lime needs key, but how to achieve this is the problem. I have wondered if I need to rough up the wall with very coarse sandpaper, or even put up a fine wire and then a layer of plaster. Second question: I have also seen lots of info on this site about what lime putty to use. I seem to gather that it needs to be low magnesium, but some people differ...?? I am just afraid of it cracking off my walls; imperfections in color and everything else, as far as I'm concerned, will just add character, but vp on the floor is not character:) Please help - thanks! Maria