Yes, it is Flornoy; "bleach-free cards guaranteed to gently yellow with age".
That
is rather an interesting selling point! Completely different mentality from - say - U.S games who do their lamination thinking of indestructibilty when maybe what the consumer wants are cards that gently yellow. My unlaminated 70s decks have (very) gently yellowed with age at the outer edges. I rather like it, it has to be said; my Rider & Co RWS, my 1JJ Swiss & Moroocan Fez.
I think the cases nisaba mentions - of brittleness & eventual shattering - must be extreme cases, surely, after centuries and centuries. My guess is that all these wonderful historic decks in the Bibliotheque Nationale, Paris and British Museum etc were on very primitive acid-free/bleach-free paper and have aged in exactly that way which some of us rather like.
I doubt any acid/bleach-free decks in my collection will brown & shatter in my lifetime.
I think I'd find something rather satisfying about my whole tarot collection browning & shattering into oblivion - so no-one else could covet it or use it - as I lay on my deathbed...