I'm back. It's been a couple of months since I've been able to take the time to stop and blog a little. June was a blur and July was just as bad. So far I've had to take 4 trips lasting several days this summer and I've had little time to be able to blog, but I'm going to make and effort to do better this month. Masonite or hardboard is a great surface. What I like about it is the warm, dark tone as a background to paint on, but we usually prime it with white gesso. Ralph Mayers' book, The Artist's Handbook of Materials and Techniques: Fifth Edition, Revised and Updated (Reference) on materials mentions shellac as a primer to paint on. Shellac needs to be thinned with denatured alcohol or grain alcohol (Everclear). When it's thick it becomes too slick and oil paint won't adhere to it, but when thinned to a watery consistency it produces a textured surface that seals the wood. I use it for smaller boards, 6 x 8 to 9 x 12. When the surface is bigger it becomes more slick and harder to paint on. You can also use the spray which is thinned and easier to use. You need to use it in well ventilated areas.