Well, it's MOSTLY paper. There are also metal, silicone, wood and plastic pieces, but it's about 80% paper. I got this a couple months ago with some birthday money, and finally found the time to build it a couple days ago. AstroMedia in Germany makes it, but I got it from Astromedia UK. The heavy cardstock is die-cut, and you stack pieces together to get the needed thickness. The chimney and condensation collector are lined with aluminum foil, to prevent the moisture from warping the paper. It works on five tea light candles. Tonight it ran for 30 minutes after a 10 minute warm-up to get a good head of steam.
https://www.youtube.com/watch?v=uTMhulOSkOc