painting direct on to plaster

hi all, quick response needed if possible. Im looking paint straight onto plaster is there any preperastion i should do to the plaster before i apply the undercoat?
Thanks

one presum su are using emulsion/water based paint.
if so

a thinned out coat of white emulsion to seal the wall( MATT emulsion)

Then thin coats rather than try and finish in one heavy coat.

Never- try and coat with silk/satin first

If oil paint is been used-- why?, but if so, a special primer is needed, then under coat, then a satin coat and finsh in gloss but this is rare requirement.

just totally painted a refurbished house i bought.....used water based undercoat(b&q's) then the real stuff over that.looks great

cheers chapies, bought a 10 ltr of atlantic cheapo stuff and have started coating the plaster with with a watered down coat of that. Any advice on painting bathrooms apart from washing down the walls with sugersoap before applying the paint?
thanks