Talas, the Bookmakerâ€™s Source for Parchment and Hides
Joyce Park stashed this in Craft
Stashed in: Books!
I love stories about where craftspeople can buy their arcane supplies. This place sounds extra Harry Potterish!
It's something non-obvious that I really like about the internet. Suppliers to very small professional niche's have always existed, but unless you are a part of that niche figuring out if there is one in your home town, or even what category to look in the yellow pages was not easy.
Today, google for "vellum for sale" and you might find a local vendor, but you'll definitely find online ones. Maybe you'll find that you get more choice or lower prices ordering it from its country of origin.
I have no need for vellum, but many things that seemed hopelessly exotic and difficult to find a decade or two ago are now just an amazon order away.