I use Masonite (hardboard) a lot. I think Grumbacher has a piece on the proper treatment for painting on it. Basically there is a LOT of misinformation regarding hardboard due to changes in the way the boards are manufactured.
The old methods involved oil and that interfered with getting a good bond to the surface.
The good news is that the stuff we get today is made using water based material and the only prep needed before gesso is to wipe the surface with a clean cloth dampened with denatured alcohol to get fingerprints etc off the surface.
I follow their recommendations and roll on 3 coats of gesso letting each coat dry before adding the next. I don't sand between coats or sand the surface prior to gesso. Makes it really easy.
I have some signs I made several years ago on hardboard that get knocked around the inside of our motorhome and propped up in the window when we park and they show no signs of chipping or flaking.
Hardboard comes in different thicknesses so for a commission I'd pick a thicker board, maybe 1/4"? A whole sheet 4' x 8' is probably about $10 and if you get it from the home center you can get the guy on the big saw to cut it for you. My favorite is to get them to cut it into 2 x 4' squares, stack them and cut them in half, stack them again and cut them in half again which gives you 12" wide by 4' pieces. If you then stack them and turn the stack sideways 3 equal cuts gives you a whole pile of 12 x 16 boards for very little outlay. If you get the hardboard with 2 smooth sides you can gesso both sides and double the amount of paintings you can do! I did this extensively when I was doing portrait classes every week.
Brian
