Monday, January 26, 2015
How to make home-made gesso!
Gesso (Italian pronunciation: [ˈdʒɛsːo] "chalk," from the Latin: gypsum, from Greek: γύψος) is a white paint mixture consisting of a binder mixed with chalk, gypsum, pigment, or any combination of these.
Gesso (pronounced: “jess'-o” is used by artists as a primer on canvas, paper, and wood so that paints and other materials will not flake or peel off. Most commercially produced stretched canvases usually are pre-gessoed.
I use it in mixed media projects such as art boxes to give a nice and smooth surface so paints and other materials will adhere. It also makes everything white so the paints look nicer.
Gesso, although worth it, is expensive (to me anyway). It can cost around $10 for 8oz. I could buy a gallon for between $20-30 but I would have to drive an hour to Portland, so that is not feasible.
As I have written in previous posts, I like to make my own materials. So I decided to make gesso. I first consulted my favourite recipe book Recipes for Art and Craft Materials and tried this recipe:
I used liquid pigment (used for coloring house paints) but other recipes take powdered chalk or dry pigment. White acrylic paint would also work fine. When using liquid, extra dry material (chalk, talc, etc.) is required.
The project worked ok but the plaster gave it a rough texture.
At the time, this was a good thing because I was making little coffin effigy boxes and wanted the look and feel of stone.
This time I needed gesso for making some art boxes. I had run out of the store-bought stuff and thought I would make some again. I researched online to see what other people used and found some had used talcum powder instead of plaster-of-Paris. I decided to try this.
I used the same recipe from the book, but substituted baby powder (smells great too!). I cut the recipe and made a ¼ which was a good thing because I ended up adding more powder to thicken to my desired consistency.
It worked beautifully! I painted it onto the surfaces and layered on muslin with more gesso. It dried fairly quickly with a nice smooth surface.
I kept it in a plastic container and when I wanted to use again a couple of days later, it had solidified (as I knew it would) to something like very firm tofu.
I tried mixing in a little water, but it still had a lot of tiny lumps. So... I put some in a small jar with three pieces of gravel and a little water, capped tightly and shook... a lot... and shook some more.
It worked great, was easy to make, and was a heck of a lot cheaper!
I really love how I can make art supplies by raiding my pantry and bathroom cupboards!
EDIT: A Facebook reader asked how archival this is. I must confess that I had not thought of that. SHAME on me! Here was my response:
"It would probably be more permanent with chalk than the talc. (I plan to get some) Since I used gelatin instead of the white glue suggested by some, it should be fairly acid free. I don't know what is in the liquid pigment on that account, but I feel it is probably safe enough. The powdered zinc pigment in some recipes from ancient times would work. Cennini used plaster of Paris with parchment sizing. The store stuff has more polymers and things to make it more permanent, but some have molded and smelled ammonia-ish when sat for a while."