Several years ago I bought a 2'x4' piece of indoor birch plywood, thinking to gesso it and paint a large egg tempera painting, but I never got around to it. I dragged that heavy piece of wood around with me from room to room and to my new studio. Finally, my newfound interest in Durer inspired me. I checked out a book from the UTC library, "Durer," a monograph by Allan Braham.
What I liked about it was that it gave precise measurements of all his paintings in inches, and I noticed that his portraits were quite modest in size. I wrote down all the measurements of all his portraits, and discovered that they easily divided into about three groups, based on similar proportions: There were a number of portraits which averaged roughly 20"x16"; another group of smaller portraits which averaged about 12'x9'; a small group of larger portraits which averaged 29"x28"; and finally one circular portrait which was about 15"x15".
I divided my panel into two 9'x12" panels and two 16"x20" panels with only a little left over. Now I"m readly to sand them around the edges and then to make up a solution of size glue. The first step in gessoing the panels will be to paint them on both sides with the size solution. This provides an adhesive surface for the gesso. I'll take pictures (I promise in the future to take extensive photos of all artistic processes!) and show all the steps in creating a period gessoed panel.