Thanks for the clarification Peter. I've often wondered about it.
Being a wheel on the end of a handle, it must be very difficult to
control whilst using enough force to imprint onto metal?
There are dozens if not hundreds of linear dot patterns, and folks
here have discussed many of the various ways to do them. As for
millgraining, for those who are newbies to it. There are really a few
kinds of tools - there’s positive and negative, and there’s hand
tools and lathe tools, and in the lathe tools there’s also rope
patterns and things. The lathe tools do work that requires more force
than the hand can generate. The key thing, though, is that
millgraining is done on an edge. Meaning that the two outer lips of
the wheel should not touch metal. Think of it as a concave wheel
riding on the apex of a triangle. If those edges of the wheel touch,
you’ll get lines along the beads, which is wrong and ugly. Either the
wheel much be big enough to staddle an edge, or more usually it’s
done along an engraved line, such as in bright cutting. Generally you
cut a line right along the edge of the metal, and millgrain that.
You’ll see what this all means as you do it…