St. Clement, Post 8: Making Gesso

"Gesso," according to wikipedia, ".... is a white paint mixture consisting of a binder mixed with chalk, gypsum, pigment, or any combination of these. It is used in artwork as a preparation for any number of substrates such as wood panels, canvas and sculpture as a base for paint and other materials that are applied over it..." A chalky-looking, plaster-like surface, it is precisely what the great Italian frescoes were painted on. And in Iconography, the veiled board is prepared with 8-10 thin layers to provide the painting surface: a blank slate, a blank white canvas, imitating the beginning of Creation itself:

"In the beginning God created the heavens and the earth. Now the earth was formless and empty..."
- Genesis 1:1-2a, New International Version

It would have been easy to use commercially prepared "Gesso." But then, creating an Icon is not about shortcuts and conveniences.

The commercially prepared gesso we found sold in stores wasn't real gesso at all, but a liquid, acrylic-and-latex-based paint for brushing on a surface, which many admit will crack as it ages.

Icons traditionally use natural materials, and real gesso is a mixture of rabbit skin glue, honey, chalk (gypsum) dust, and marble dust. Made correctly, it has the texture of tofu, and is 'rubbed,' rather than 'painted,' on the surface of the board.

So, I collected my natural materials and decided to make my own gesso. the effort was complicated, of course, by the fact that no two web recipes suggest the same process. Some suggest a 3:1 chalk to marble dust ratio; others suggest a 50/50 mix. Many require that once everything is mushed together, that it be strained through cheesecloth to eliminate lumps (with little help figuring out what to do once the cooling rabbit skin glue begins to gel and harden and clog up the holes in the cheesecloth!) And through it all, the rabbit skin glue needs to remain warm...AND one must avoid actions that introduce air into the mixture.

So, I followed the same philosophy I use when I cook: check out all the recipes, and then come up with something of my own based on what 'feels' right.

The same day I veiled the board, I made extra rabbit skin glue for the gesso. I figured the easiest way to avoid getting air in the final mixture was to make it directly in the container in which I hoped to store the finished product. I used a square tupperware container, and placed it in the middle of a larger glass baking dish filled half-way with near-boiling water. I placed this contraption on the top of the stove, with the burner on very low. I poured the prepared rabbit skin glue from the pot where I had 'cooked' it

into the square container (filling it 1/3 of the way), added a tablespoon of honey, and let it dissolve. This kept the rabbit skin glue warm and highly liquid, without boiling it.

Then I needed to add my "Whiting" mixture (the chalk and marble dust - I went with the 50/50 mix), without any stirring that would introduce air to the mix. So, i went with an old-fashioned contraption: a small, one-cup size flour sifter with a little crank handle. Slowly turning the handle, I sprinkled the whiting mix over the surface of the glue as if I was spreading confectionery sugar on a cake.
As it hit the surface, it became saturated with glue and sank to the bottom. I continued this for about 45 minutes, until the whiting actually reached the top of the glue. I placed plastic wrap directly on the surface of the glue-whiting mix, attached the tupperware cover, lifted it from the baking dish of water, and placed in the refrigerator to cool overnight.

So for an entire night, I worried.

Was a 50/50 mix the right mix to use? Were there air bubbles trapped beneath the whiting? Was my glue too gloppy to begin with? Should I have pressed it all through cheesecloth anyway...after all, how do I know whether or not the whiting 'clumped' beneath the surface of the glue?!

the next morning I approached the refrigerator with fear and excitement. i popped off the cover, and peeled off the plastic wrap..and gingerly touched the surface of the substance.

Tofu-like to the feel. We made gesso! REAL gesso.

The next step? Applying layer upon layer of gesso to the veiled board...hopefully, this weekend.....