Gutjahr ought to get his facts right, Jehovah's Witnesses did not exist in the 1920s and therefore could not have "invented" Bible paper. There is a faint possibility that it was a Bible Student who was also a paper technician who developed Bible paper according to the demands of external publishers. Did the Watchtower Society even print Bibles back in that decade? I don't think they did.
Well spotted Half banana. Bible Students and even JWs didn't have an agreed upon bible until the New World Bastardization was published.