Experimenting with new materials: Sinopia Casein Gesso

Materials: Sinopia Casein Gesso. Aluminium composite, birch, Gator (brand) foam board, and Masonite (brand) panels.

I applied Sinopia's casein gesso on unprepared surfaces because I wanted to find out if whatever that was in the substrate could over some time migrate to the surface of the casein gesso layer. I am assuming probably not because some of the ingredients in their casein gesso are oil. However I think a first coat of PVA as a barrier would be wise if you're going to use any water based medium like watercolour, gouache, or acrylic. But there is no doubt that everyone can agree that the aluminium composite panel will not be a problem.

The casein gesso is not opaque so at least two coats is required for a full coverage. I also applied gesso to the edges of the foam board to seal it against direct contact with mineral spirits because the foam would deteriorate if it comes into contact with it. By the way the casein gesso smells delicious.

Casein gesso applied to different substrates. The black foam core panel (top right) demonstrates this casein gesso's translucency. At least two coats will be required for a full coverage. 

Foam edge treated with casein gesso as barrier to prevent direct contact with mineral spirit or turpentine. The foam will deteriorate if contact is made.

Single coat (left) versus double coat (right). 

This casein gesso dries quite quickly. I will lay down a third coat and then lightly send it for a smooth finish. Like the rabbit skin glue based gesso, it is ideal for rigid surfaces. Similar to rabbit skin glue based gesso it should work well with watercolours, and gouache, but without the funky smell when it gets wet (think toe jam courtesy of urbandictionary.com). I have several panels prepared with the casein gesso so I will have enough to experiment with watercolours, gouache, graphite or charcoal.

More information on this product at http://www.sinopia.com/Casein-Gesso. Sinopia is not a high profile artisan so it's quite easy to forget they exist until you make a few purchases of their good stuff. You know, out of sight and out of mind. They have an Instagram presence as @sinopia_pigments.