History of laser engraving article
Posted: Mon Nov 25, 2019
This is from the Engravers Journal magazine which has online copies available. It is numbered '5' and I will be researching this when time permits. [ Oh yeah... I am retired 
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https://www.engraversjournal.com/legacyarticles/2244/
]https://www.engraversjournal.com/legacyarticles/2244/