Cuir-bouilli, which is Leather boiled or soaked in hot water, and, when soft, molded or pressed into any required form; on becoming dry and hard it retains the form given to it, and offers considerable resistance to cuts, blows, etc.
The word was in common English use from 14th to 16th c., after which it is not found till modern times, when it appears as borrowed from modern French.
Seeing where the current baronial coronets are metal, and tend to be heavy, I decided to make a new pair for our Baron and Baroness. During the process of the inserting the cut-out leather for the molding part of the project I learned a valuable lesson. Make sure that the leather you decide to use is thick enough. My first try I used veg-tan leather that I typically use for making quivers or bracers, so it is around 6 to 7 oz leather. This ended in quite an interesting result. Not only did it harden the leather once molded, but it caused the leather to shrink to something that was way to small and made it very brittle.
Upon learning that the 6-7 oz leather would not work, I needed to get some 8-10 oz leather and recut the leather and make a second attempt. This resulted in a much better rough coronet, that while it did shrink a little, it did not make it unusable.
With this proper thickness I was able to continue to make the coronets and the result where to the satisfaction of their Excellencies