I was thinking of going in that direction , good info . Thank you for sharing .

This is when you glue cavens over playbord and then the cavens is treated with a thin layer of ground , and you paint on a cavens .But in the 14, 15 ,16 century they used a thick wood panel covered with a thick layer ( realized in stages) of natural gesso.

Back then the cavens was also involved , but NOT this tipe of cavens , but a cavens where the strings of cavens have spaces one of another (like today medical bandages ).So , using this tipe of cavens is ONLY to form a stronger structure with the thick natural gesso . So : The firs tipe is painting on cavens , even the cavens is glued on a playbord. The second tipe is painting on wood , (treated with natural gesso ) even the rare string cavens is involvd !