The article mentions that Mr Hipschen is a faculty member of the intaglio engraver academy in Urbino Italy. Here is a youtube link to a video uploaded by Emily Gordon of Bruno Cereboni-Bajardi of that academy talking of their work
JJ- During a private (just me) tour of the Bureau of Engraving in 1993 ('94?), I met Mr. Hipschen and we 'talked shop' for about 15 minutes. In front of his workbench he had what was basically a very large light table (like drafting table size) turned up on edge, tilted forward over his bench at about a 60 degree angle. It was like having the most perfect 'north light' all the time. That's where I got the idea for my own bulino lighting diffuser set-up.
btw- he was engraving the new larger portrait of Ulysses S. Grant for the new $50, back when all denominations were being revamped. it was pretty cool to see that about two-thirds finished.