I've been trying to find a way of simulating old items made of horn (medieval windows, lanterns - 'lant-horns' - , viking drinking horns for quaffing ale, hunting horns, spoons, bowls, etc). In medieval times the outside sheath of cow horn was used just like we use plastic today - it could be cut, heated and shaped, and was waterproof and semi-transparent.
My attempts to make this with polymer clay failed absolutely. No surprise there :)
In my search I've found an interesting product. This is mica, which can now be bought in nicely packaged pieces. Mica is a natural product which can be split into thinner and thinner layers, depending on what you want to do with it. The colour is darker when it is left thick. The thickest piece in this pack is almost 1mm thick, and it splits/delaminates into at least 10-12 tissue-thin layers.
It has interesting natural patterns in it, which make me think it is a reasonably good old fashioned window glass. On an angle it is quite wibbly like old glass. It can look a little like brittle plastic, but it's still nicer than perfect acrylic or perspex.
This Mica Sheet pictured can be bought online in some scrapbooking websites, also on eBay.
Evidently it can be cut with scissors, diecut, punched, stamped, inked, embossed, heated, gilded, painted, etched and stained to resemble coloured glass - I'll have to try this last bit . . .
Anyway, to the point - the company which makes this, USArtQuest, also makes a product called Micacraft Sheet which is reconstituted mica - and this is an orangey 'horn' colour, and it is also able to be heated and bent (you can't bend the ordinary mica sheet). So when I get around to buying some I'll let you know if it works :)