We used True Gesso boards for the egg tempera workshop. Nice boards--well back-coated, relatively smooth finish, and not many pinholes. The board is positioned on an easel made and sold by Koo Schadler and her husband Jeff.
Here is a closeup of the surface in raking light.
This photo was taken after a light sanding with 400 grit and a wipe down with denatured alcohol.
Here are the makings for a batch of Prussian Blue pigment paste.
I'm disbursing the pigment on a glass palette, mixing in distilled water with a palette knife.
Here's the final product, ready for the jar.