The top surface paints fairly well, it is the edges that usually suck up paint. Using a primer or sanding sealer will help a great deal. If those are hard to find, several coats of a plain color will also work. Put a few coats of paint, then sand lightly, then more paint. Repeat until the paint is smooth and not soaking into the "wood". Oil based paints will soak in less, If I remember correctly.