Painting - what drywall primer?

I have freshly taped & sanded rooms ready to paint. I've heard & read everything from just double coat the latex paint to regular latex primers to special sealers. Whats the usual route? And how dust free should the walls be?

I vaccuum the walls with a shop vac. You could wipe them with a damp rag. Some folks just paint over the dust.

Primer provides a seal for the wallboard's surface and a bonding surface for the paint. It is not the same as paint. It keeps from raising the nap of the paper. Besides, it is cheaper. A good coat of the same brand of wall board primer as the paint you intend to use will help the finish coat cover and make the most of the uniformity of coverage. You may well get good results with one coat of paint at $20 a gallon on top of a coat of primer for $10 a gallon. If you put on a coat of paint on the bare wall board and it raises the nap, the second coat of paint won't fix it. You would likely need to sand off the fuzz.

Hope this helps.

One of the issues here is that the drywall mud and the drywall absorb paint differently. Using a PVA drywall primer that sits on top rather than soaking in, evens out the absorbtion factor because the paint sits on top of the primer rather than soaking in.

shop vac and wipe down the walls with a damp rag.all that mud dust is like putting flour in a baking pan so the batter wont stick,same thing for the paint and ive seen paint failure for that reason alone before.prime the walls with a made for drywall primer,most are,just a tidbit use a waterbased primer ive seen oil base raise the nap more than waterbased.then do any spot patching that you feel is necessary.you can see all the inperfections once everything is primed.then sand all the walls lightly with 220 grit to get any fuzzies off and prime again.sand again with 220.this will give you a nice smooth and durable surface with no chance of mud patching flashing through the paint.