At the faire, those tights were referred to as "dragon skin". As to what it really is, I'm not sure. It's a stretchy, patterned fabric with a rough leather-like appearance. Unfortunately the vendor at MDRF can't get it anymore, so I'm lucky I got it when I did. If I didn't have those, I'd probably have looked into some brown wool chausses, or joined hose, or something like that. Or leather chausses.
This is the "woodsman" outfit I put together a number of years ago, with a Robin Hood sort of look in mind. As soon as I ordered "Albion", I knew I'd be doing a photo-shoot like this as soon as it arrived.