I have a roll of oil-primed linen canvas that I use for my larger paintings, so I decided to use some of it to prepare boards for the studies that I would like to place for auction. My husband cut 6" x 8" pieces of 1/4" birch plywood and sanded down the edges. I cut 7" x 9" canvas pieces, which are one inch longer than the plywood on each side. I cleaned the wood with mineral spirits and then applied an even layer of acid-free glue to the board with a flat paintbrush - common glues used for this purpose are Yes! and Miracle Muck. Then I applied a thin layer of glue to the backside of the canvas and paced it on top of the board, making sure to remove all air bubbles by pressing the board with my hands in an outward motion. Next, I turned the board face-down and put a heavy book on top and allowed the glue to set overnight. The next day, I cut the excess canvas with a craft-knife and lightly sanded the edges with fine-tooth sandpaper. Now I have a supply of rigid canvas boards that are easy to paint on and will hold up well in the mail.
A step-by-step guide for mounting canvas to board can be found on the Oil Painters of America website.