Hi,
I visited the Cloisters this weekend, which is a part of the NY Metropolitan Museum of Art. My main purpose was to closely examine bone and ivory carvings for their construction and evidence of paint. That mission was accomplished. I bought a small book in their bookstore titled “On Divers Arts” by Theophilus. Theophilus likely was Roger Helmarhausen who was a master metalworker during the mid 1100s. The book describes methods of making pigments for paint and stains, glassmaking, making illuminated manuscripts, and all sorts of metalworking, gold and silversmithing. The work is by someone actually working in the trades as a highly skilled craftsman and decorative artist. I learned that resin and linseed oil varnishes with copal and softer resins were widely used at least as far back as the 12th century. Red madder tinted linseed oil varnish was used to tint woodwork back then. Hand gravers look just like they do today and were hardened the same way. Case hardening was the norm for iron-made objects because steel was rare. Very little in the book is alchemic or “magical”. However, if you really want to harden steel and carbonized iron really hard, prepare the following quench: take a small goat and do not feed it for 3 days. Then contain it such that its urine can be collected and feed it ferns for 2 days. Use the urine for the quench. Almost as good is the urine of small red-haired boys.
dave
