Glue sizing and oil priming are the traditional methods of preparing a canvas for oil painting. The size is made by dissolving 1 part Rabbit Skin Glue to 13 parts cold water.
Soak overnight or until all the water has been absorbed by the glue.
Heat gently in a double boiler and stir until the glue dissolves (do not let the glue boil).
Apply while still warm with a stiff brush.
The size acts as a penetrating liquid to fill pores of the canvas and isolates the fabric from subsequent applications of primer and oil paint preventing canvas rot.