An antiqued bronze finish is made by putting a colour on and then taking most of it off again.
The metallic layer goes on first over the whole carved surface. Then a dark glaze is brushed over it and worked into every recess and undercut with a stiff brush, so it collects in the deep parts of the carving. Before it sets, the raised work is wiped back with a cloth - the leaf edges, the crests of the scrolls, the outer curve of the plume - until the metal shows through again.
How hard that wiping is done decides the whole character of the piece. Wipe lightly and the frame stays dark and quiet; wipe hard and it becomes bright and lively. Our artisans work to a sample panel agreed with you before touching the mirror itself, because there is no going back to a lighter result once the glaze has cured.
The finish is then sealed. What you get is a frame that looks like cast bronze that has been handled for a century, on a piece of timber that will still be flat in a century.