Staining will be difficult with MDF, I would imagine and there is no grain to make staining stand out. However, once sanded and sealed, MDF provides a great surface for acrylic painting. I use MDF for most things that I am going to paint. You don't require particularly thin washes, one or two coats of barely thinned acrylic will give you a lovely finish. End it with a stingy spray of varnish and it should look great!
Sue |