AVOID using paints that contain latex as the latex will seal the surface and prevent the plaster from drying as it should (If using a paint that contains Latex the plaster will dry behind the paint and push the paint off the wall). Contract paints (not vinyl matts) will be the prefered choice.
Thinned with water 50/50 artex sealer from B&Q or wickes plasterboard / plaster sealer in 6lt tubs. Using that now on plaster I skimmed. Both work great and cost effective. Been using for years no trouble. Do not use Pva
Information about painting new plaster, when you can safely paint the plaster and how you should go about painting it so you get a great finish.
Bare Plaster Paint................a sales marketing gimmick that works in the DIY market place bringing in the dosh!!!!
It seems to me very little on the market specific to sealing plaster. Seems the few available are being sold as plasterboard/plaster sealer ment for the dry lining market. Wickes. Artex sealer and Gyproc are the main ones, plus Dulux sell a plaster sealer in 1lt tins.. Some use standard WB undercoat I here.. I'm using the wickes stuff mostly,and I do water it down. It's cost effective and seems to work well. 90% if Decs just thin the first coat of emulsion but it can flash with patches, but this depending on the type of paint. I avoid contact emulsion even on recent plaster skims. When dry I seal, leave 24hours and paint 2/3 coats with a premium emulsion. I also seal all contract emulsions prior to a quality paint being applied. I hate contract emulsion and never use. I guess I'm not in that market though.