A brief look at the tools and techniques :
The simple tools have changed little since the 15th century.
The main cutting tools as the chisel, the graver, the onglette, the gouge, all designed to incise the metal in different profiles. The diamond-point chisel cuts with its lower edges and incises a V shaped groove. The gouge hollows out rounded grooves and the flat chisel ( French : hachoir ) is used to remove larger portions of metal. Those tools, with a steel handle, are pushed by the hammer, in the manner of Liege. In the « Liège » manner, all these tools are steel-handled and struck with a hammer when used. Elsewhere, similar tools are fitted with wooden handles and the engraver pushes them into the metal by hand pressure alone.
Another distinct category is that of the chasing tools. These are punches tipped in various shapes and designs. They may be rounded, flat, chekered and beaded, etc… (Fr . : matoirs, perloirs, bouterolles, planoirs etc…) and serve to tamp the metal instead of cutting it. The relevoir is a special tool used to raise the edges of those engraved lines that are to be inlaid. (See « Inlay » below)
Rifflers files are used to smooth the cut metal, scrapers scrape the surfaces and burnishers polish the metal with a crushing action. Grindstones and oilstones are necessary to sharpen tools, magnifying lenses aid small work and most importantly, a vice which swivels in all directions must be used to securely hold the work and to enable cuts to be made in any direction.
To this traditionnal tooling, the new techniques of machine milling and pneumatic graving may be added, but the essence of the work remains the same as ever.