The Voynich Ninja

Here's how: if the manuscript had been created by an isolated community, they would have slaughtered their own animals to make the parchment. By the way, it's definitely NOT "vellum" even though it's calf: "vellum" is a very particular type of VERY fine, thin parchment made from newborn or even unborn calfskin. This is calf, but not vellum.

There are LOTS of manuscripts made of terrible parchment.

Also, the McCrone report identifies the ink as Oak Gall, so nothing unusual there. On p. 3 of the report, "All of the inks used for text and drawing were identified as iron gall inks."