Remember, the floors were sanded and prepped with one coat of oil-based sanding sealer. I then vacuumed and tack-clothed the floors and applied - over two days - three thin coats (THIN coats are very important!) of latex floor paint (from Clark Paint) in Benjamin Moore Dorset Gold. Love the color. Love.
But........... (you knew that was coming, right?) I don't love gaps between the boards. The dark lines between the boards have a very 'cottage-y' effect, while all the photos of painted floors I like show very tight boards with a consistent color and uniform glossy surface.
We thought about applying caulk to the nail holes and between all the boards. We wondered if the soft pine floors would contract and expand a lot, making caulk between the boards irrelevant, so I called Clark Paint to ask for advice. They suggested a very high-quality paintable caulk between the boards. They didn't think floors would expand and contract too much. They recommended DAP (I think that's the brand name?) 35 year latex caulk. Then ANOTHER EFFING coat of paint to cover the caulk, THEN the polyurethane.
I keep thinking 'a thing worth doing is worth doing well', but I have to say: the thought of crawling around on my hands and knees caulking all those floorboard makes me want to cry a little. I think I'm just tired of not having a kitchen. I'll feel so much better when there is a hooked up stove out of which something warm can come.