On Wednesday, November 27, 2019 at 10:31:11 AM UTC-5, wrote:
I finish interiors with acrylic enamel from the auto refinish supply store. I buy a flat gray. It uses a hardener. I apply with a small roller. The roller leaves a slightly roughened surface that hides all the little flaws and makes it look "finished". FWIW UH

Acrylic versus urethane for interiors? Comments please.

Raul Boerner

I actually use AU(acrylic urethane) but AE (acrylic enamel)works fine. Texture resulting from roller application makes more uniform finish.
Some suppliers may be limited in which products can be provided in semi flat.