I would never attempt to "contrast" the whites. I think it would be very hard to do so without one of the whites looking dingy or at least "yellowed." If you're concerned with whether the moulding will stand out enough, trust me, just the difference between flat and semi-gloss will make it stand out. JMHO

Thank you all! OK, another crown molding question, please. What would you guys do? This is the situation: We are in process of a huge kitchen remodel. We removed the wall between our kitchen and dining room, now it's nice and open but still seems like "two rooms", I guess because the floors will be different (the dining room has an oak hardwood floor) and also because there is a supporting beam and bulkhead (soffit) at the ceiling between the two "rooms". Soooo, if I put crown molding up in the kitchen, should I carry it through to the dining room, too? I'm OK with that, and I think it would look lovely, just wondering your thoughts? But MOST of all... if I do it in both of those rooms, what about the living room? Our living room is off of the dining room, through a large archway. However, unlike the kitchen and dining room, the livingroom is BIG... and I was thinking of putting 6" crown molding up in there. BUT, I think 6" would be too wide in the kitchen/dining room area. SOOOO, how important is it that the crown molding be the same size, between rooms that are visible to each other? PLEASE ADVISE! Thank you very much! Lynn

Liquid nails will work fine, if you anchor the bottom to the studs, the molding will never move in your lifetime. Use phenoseal latex caulk to fill any voids between the molding and the ceiling/wall. "First, you need to discover what is supporting the ceiling." This makes no sense. Crown molding reaches out into the ceiling 3 or 4 or greater inches depending on the crown molding size. There is 16" between joists, so the poster is saying his molding is in this void area so he cannot nail the top of the crown molding into anything other than sheetrock.

I'm surprised the installer didn't address that during installation. I would have used an extra piece of trim, in the same color and flat, and installed it behind the crown molding. Thus, there would be a flat white area where the gap is. Yes, it would still create a visible line, but much less visible than a shadow or gap. Since the crown is already installed, caulk.