Could be a water slide decal under the clear or over. There is another way that it is done that I am aware of. Hot foil used in conjuction with a vulcanising machine and typeset. Kingsley made a machine to print with hot foil on greeting cards, pens and about anything you get under the press. Check them out on ebay might work great for you. Could be a military type stencil also Creek Chub lures used military stencils early on, and the foil later. I am sure there are other ways also, that I am unaware of. That someone else might come along with