The materials work involved navigating

The materials work involved navigating

the labyrinth of the older texts, but also the new, generally more reliable research from technical art history.

paint by number kit technical art history has made some fascinating discoveries, such as the use of a cooked starch gel by Rembrandt.
I've learned the value of making good notes.
And many tests.
At first I made the hard resin varnishes: copal, amber, and sandarac. But, while complex pyrolysis is a great way to stay in touch with one's inner ten year old, these materials all darken over time.

About paint by number kit,I also experimented with the infamous mastic gel mediums, very seductive to work with but, again, unreliable over time.