As I've been playing around with egg tempera lately, and egg tempera tends to slide off acrylic gesso, I decided to give the real stuff a try.
I'm not a veteran using traditional gesso, and there may be other better approaches out there, but I do my research, and this method should be sound. It's now been about 72 hours since I prepared the board, and it didn't crack or develop pin-holes. I must say though, the prepared board is flawlessly chalky smooth -- although I might find a pre-mixed traditional gesso/size just-add-water mix, I doubt I'll use acrylic gesso in the future.
Also, it should be clearly noted that traditional gesso is too brittle to be used on fabric supports.
All this being said, here's what's happening: a perfectly rough board will be sealed using size (rabbit skin glue in water), and then it will be covered in layers of size mixed with marble dust (calcium carbonate).
I used just three ingredients: water, marble dust, and rabbit skin glue (granule form).
Rabbit skin glue - big bag of granules for 7 dollars
Marble Dust - huge bag of the dust for 3 dollars
Water - I used the hot water from the hot water dispenser on our bottled water cooler. You should probably use distilled water that you have heated to boiling and then let cool for a second or two. If the water is too hot, it'll destroy some of the adhesive properties of the rabbit skin glue.
First, you make the size. This is just glue and water. It's going to seal the grain of the wood and provide a good surface for the gesso. There's a lot of talk about using double boilers or letting the granules soak and so on. The instructions on the back of the rabbit skin granule package just said to add hot water. That worked, and stayed perfectly liquid for several hours.
I added one and a half tablespoons of rabbit skin glue granules to one cup of hot water. The water was as hot as it comes from the hot water tap on our bottled water dispenser. It's hot enough for tea as it comes out of there, so heat accordingly, or boil and remove from heat completely.
I stirred gently as I slowly poured in the glue. The granules dissolved nicely.
I applied the size to the board. I didn't just paint it on; I scrubbed it into the wood with a housepainters brush.
Then I sanded this first coat. It dried after ten minutes or so. I sanded this first application and then applied two more coats. I didn't sand before added these.
Now that the board was sealed with the glue (sized), I proceeded to gesso. To make the gesso I added the marble dust directly to the size mixture, accounting for the used-up size. You could mix up a fresh batch, but the gesso is simply size mixed with clay, whiting, gypsum, or marble dust.
I added on cup (8oz.) of the marble dust. At first I added only about 6 ounces to account for used-up size, but it didn't seem all that opaque, so I added the rest. It worked fine.
I added it a little bit at a time and stirred gently. Purists do everything they can to avoid air bubbles, but rubbing the gesso with water, as I outline later on, takes care of the pinhole problem anyhow. Actually, I shook the mixture gently. Many caution against this, but I didn't run into problems.
The first coat I applied in a scrubbing manner.
Then, I used my fingers and worked it into the grain.
The first coat looked worryingly thin. I kept building up coats. Things started looking great. I sanded very lightly with a fine fine grain sandpaper in between each.
Eventually the gesso mixture began to thicken. I placed the container in another container with hot water. The thickening reversed at once and the material stayed extremely fluid. In the future I'll do this right from the beginning.
Despite the layers and the sanding, there can be little imperfections and pin holes in the gesso. For many, this isn't a big deal, as they enjoy the imperfections. If you want a pristine surface, this can help. Wait for one of the final coats to dry. Then, wet the surface with water (not the hot stuff, just water), and rub. The water melts away a little bit of the gesso and as you rub gently with your hand (kinda like sanding) you take this thin layer of melted gesso and smooth over all the pin-holes (often these don't show up till much later when they are present). Then, just let it dry and proceed with the next layer as you normally would. You just need to do this once.
Eventually, in between doing some painting, I ended up sealing this particularly grainy panel with about ten coats (sanding lightly between each). The end result is absolutely the smoothest matte painting support I've ever felt. It also has a good amount of grab to it.
Each coat dried quickly, so I really didn't mind all the layering. Either way, the surface is nothing like acrylic gesso -- I knew they differed, but I hadn't realized how drastically different the traditional gesso is from the acrylic stuff.
After about 48 hours any imperfections or cracking or whatnot should surface. If your panel is still looking great at this point, it should remain that way indefinitely. This particular panel was just about the grainiest thin plywood surface I could have found, and if I was sealing untempered masonite or something nicer like that, I could have used far less coats. I think most go with 2 coats of size with sanding only after the first coat, and then 3 to 8 coats of gesso.
Thanks for looking!
Fine Art by Craig Houghton