We have come a long way in getting your Maglite engraved with your logo. Before laser engraving, marking metallic objects was done with a mechanical “scratcher”. Jewelers used to do it that way, and may still do it. I don’t know. It’s cheaper than buying a laser engraving machine.
Today, many Maglites come in color that is anodized onto the aluminum barrel. The laser cuts through this anodized layer, exposing the bare whitish aluminum. This results in your white logo neatly placed on a colored barrel.