Chisel is a word that identify a complex set of techniques to make textures on a metal sculptures and also the tools to realize them. What happen if you must make invisible a welding on a complex surface, or if you have to engrave a free hand signature of an artist ? obviously machines cannot help you so much , so you must be good at chisel. And is a thing you can do only by hand.
First of all you must learn how to make a steel chisel on the anvil , shaping it with a hammer from a steel bar and tempering it in the right way. You must know how to make the tool for fine textures, the one to engrave, the one to mark straight and curve lines and so on. Each and every one of our workers in the finishing department have a special place on his desk dedicated to a bunch of little steel chisels. There is not a standard set , and except for two or three kinds that everybody must have is the need that determines the type and amounts. also they tend to be accumulated, so some workers have forty to fifty chisels !
But making a tool is not enough, so you have to identify which kind of surface you have to reproduce and ind which way. Chisel in practice is a little sculpture in the sculpture, but in the end all is done to make this work as invisible as possible ! In fact all must be in harmony with the project and the work of the sculptor, as we cannot add or subtract nothing from the sculpture.