3" x 4"
I've just finished making panels for my next painting frenzy. I followed the step-by-step directions on Stapleton Kearns site. They are not hard to make and I can make enough to last me several months in a short period of time. I bought a table saw at a garage sale for $75.00 and it works great. If you are an artist I'm sure you already know about Stapleton Kearn's blog. It is chock full of great information (with a side of dry humor).
Another thing I did was go to the lumber yard and buy trim pieces so I can add "picture rails" to my painting room. I added two rows of rails so I can get my paintings off the tables, off the chairs, off the floors. You know what I mean.! Very easy to put up with hubby's help.