I guess if you know the dating techniques, you know how to fool them. Kinda test-driven development.
He would take pages from old books. The blank pages at the start/end, etc. Not sure how he spoofed the ink
IIRC, you can either recreate the ink from a recipe, find old ink and re-dissolve it, or if you have the patience you can extract it from old pages.
“Hofmann also learned how to manufacture inks using the same components and methods used by contemporary artisans.”
https://www.ioba.org/standard/2002/11/genuine-fakes-mark-hof...
How was Hoffman able to forge letters that were supposedly 100+ years old? Wouldn't modern materials dating techniques reveal the fraud immediately?