Thanks Marlon. I start with an angled craft knife blade (about 1/4" long), pushed gently over the pencil lines, then I deepen them, by pushing down into the line with the pointed edge of a graver. This grade of Ureol doesn't like the graver pushed, so on curved lines I pull the front edge back along the line. So rather than be cut, they're impressed into the surface. In brass, I just push engrave, using the same graver. You can make gravers from broken Swiss files on the grinder or you can buy them as gravers from Squires. I also have a few escapement files, which I got for pennies at the Sunday market. These are incredibly fine, so I can use the square one or the triangular, edge on to lightly follow the lines through. Escapement files can be up to £37 each! I got a handful for 50p!