IMO... You'll have to prime & paint that ceiling! Use a good, Flat white, or LIGHT coordinating color in Flat. Don't put any water or oil Poly up there!! It would be very messy, & impossible to get even. Rule out the Gardz for this as well, although it CAN be used as a primer. Traditional primers would serve better here though. >>> One option...C2 has a "Dead-Flat" paint that might be useful on this ceiling. You could have the White-base tinted to a very light color, and in "dead-flat", it would be very rich up there! I just wouldn't leave the ceiling as smooth Joint-compund only. It's not plaster...it needs to be coated with primer & paint, or any cleaning would be a dusty nightmare! Definately use a 1/2" or 3/4" roller to apply! You'll be re-loading every 5 seconds if using a 1/4"!! These will leave some stipple...unless you're gonna have it sprayed?! Faron

You only need primer if - -- you're painting new drywall, metal or wood -- you're putting a drastically light paint over dark paint or vice versa -- there was extensive damage to the walls that was repaired and you have large areas of raw, new surface plaster -- you're painting surfaces that are very dirty (or smelly) and cannot for some reason be cleaned -- you need for some reason to add to the waterproofing of the underlaying surface So, you should be fine.

So my painting knowledge has multiplied by about a factor of 100 over the last month or so as I'm doing most of the painting for our renovation. I've painted almost every surface you can imagine, and fortunately the professional painter we hired for the ceilings has been so nice about giving me tips and suggestions. On the subject of brand of paint: Everyone seems to have their favorite and if you have one, then stick with it. I prefer Benjamin Moore or Sherwin Williams. I used to use Behr but once I used BM I never looked back. I sometimes use SW because they have coupons in the paper. My go-to paint is Benjamin Moore Aura. I like matte for walls and satin for woodwork/trim but that's totally a personal preference thing. Make sure you read the directions for the paint you're buying. For instance, with Aura, when you cut in, you want to cut in, let it dry completely, then roll in. This is different from most paints which want you to keep a wet edge on the cutting in. On priming: I don't care what a paint claims. I prime. I'd rather spend a few extra buck and a little extra time to ensure that it will be a good job that lasts than have to redo it in two years. On cleaning: Buy a product called Dirtex at the hardware store to clean whatever you need to. It's perfect for cleaning before painting. And my last tip: by really good brushes. I've got a set of Omega brushes now that cost about $28/each. I take good care of them and they are amazing. Worth every penny. And certainly a money saver as I would have purchased many lesser brushes by now. Oh, and on the paint matching. I got a BM color mixed in SW paint a couple weeks ago. For some reason I thought all these companies had each other's formulas in their computers, but that was not the case. They ended up scanning the color chip and matching it from that and it took three tries with it. That was a little worrisome for me. If you REALLY love a Behr color and you want it to be exactly that color, I'd probably use Behr paint.

good point Jan. yes, are we talking about actual plaster or about drywall that has had skim coat or 'joint compound' applied? An actual old school plaster is not the same as drywall compound. And you shouldn't be doing anything to 'fix' it. if it's regular drywall and skim coat, and you paid someone to do it, then they should be responsible for smoothing it out to where it's all flat and plumb. And normally they apply the primer coat. however, if you have to do it, and it's really drywall compound, then yes, get a 'drywall sand paper' and go to town. (make sure you wipe up all the dust from everywhere before you paint)