A: Sort of depends. When I built the large panels, had to do pinhole fills so when all was sanded, used commercial primer sealer which was sanded smooth. Usually just gesso direct. Paint with oil and alkyd, alkyd medium. All my gessos are acrylic. Usually do a clear sealer on back sides, not always. Baltic panels are very stable. Larger panels get 7-8 sanded coats, smaller 4-5.
Q: What kind of panels do you use?
Baltic birch, or double tempered masonite only... Favorite small panels are double tempered masonite, with edges smoothed and well grounded makes the best panel for up to about 10x12". It is extremely stable, and I love it. Have used it for decades. Anything beyond that size I go to 5mm baltic birch. I bought a lifetime supply of it in Seattle, and use smaller paintings un supported, and larger ones supported ("cradled"). Some of the large ones were done with 3mm supported for weight loss, and I wish I had picked up more of it.
Q: Gesso?
A: The large 48x60" panel in the pictures has 5 coats of white Liquitex gesso. Finished withtwo coats of grey tinted Speedball gesso, sanded between. My first few coats are Liquitex, which is heavy and a bit more plastic. Final coats are neutral grey Speedball gesso, which is thinner but sands better. It is much harder.
