The Opera Varia of St. Ambrose Includes 12th Century Images of the Processes in Book Production

A twelfth century manuscript of the Opera varia of St. Ambrose in the Staatsbibliothek Bamberg (Msc.Patr.5) contains a full-page miniature containing 10 circular medallion-type images depicting the processes of making a book from preparing parchment to binding. The binder is shown using a sewing frame. 

Digital facsimile from Staatsbibliothek Bamberg at this link.