I'm getting ready to repaint in my bedroom, and I smoke. (Please don't go off on me...I'm aware of the risks to my health.) I last painted in there about six years ago with a high-quality latex over primer. The walls are plaster rock. (Don't ask...I have never heard of this before either. Basically it's impenetrable stuff.) I'm trying to do this at the lowest cost and with the least amount of energy. I have washed the walls with muriatic acid but there's no difference in their appearance. After researching on the 'net and talking to the Sherwin-Williams guy, this is what I have decided to do: Paint the walls with a tinted, oil-based primer, of good quality. Probably Cover-Stain oil based primer from Zinsser. The thought is, if the color is in the primer, no finish coat of paint will be needed. I'm not looking forward to dealing with oil. Does anyone know of a latex based primer that would also work well? Preferably one with low VOCs? Does anyone think I have to go to the extreme of painting with shellac based primer (B-I-N) first before painting the color on the walls? My Sherwin-Williams guy seems convinced this is not going to be necessary. Thank you so much for any help...I'd rather not be out of my room for longer than necessary.