We still do quite a lot of diamond dragging on metal plates. Mostly brass and nickel. The materials like black brass and aluminum I try to get on the laser whenever possible, but there are still many customers who want it scratch engraved. We do plaques for a local county Fire and Rescue Department. I've tried to get them to switch to laser engraving, but they'll have no part of it. Each plaque takes 45 minutes to run - mostly because of the logo. They pay more because of this, but it's what they like so it's what they get.
We also do diamond engraving on cylindrical items. A lot of perpetual trophies, bowls, cups, etc. I know of only one other place around here that can do these, but it is a national chain and the work they do is sub-par at best. About the only thing we can't do are items for which a fiber would be a necessity. There have only been a few of those, though.