We're producing high quality steel castings which are then hot dip galvanized, so the surface has a layer of zinc in addition to the steel. We need to cast some basic branding and size details into the product, with a slightly raised embossing, and I can't get any sensible info from anyone with regard to what sort of detail the casting will tolerate. Don't know how to define it, maybe in terms of the thinnest line that can be reliably reproduced, or just e.g. 50 DPI. Anyone got any suggestions?