The 'X-Federation' chair by New York-Based Designer Victor Vetterlein uses a combination of laminated wood, combined with carbon-fiber to achieve a very slim and minimal look without compromising the weight-bearing function a chair requires. The technique first started in boat building and was further developed in the skateboard industry, which is where I first encountered this technique but was somewhat skeptical. (I have 2 Sector 9 Cloud 9 skateboards, very thin wooden veneer decks. Very maneuverable and a joy to ride. Sector 9 doesn't seem to make them this way any more. They use fiber glass now. Here's a that proves the strength of this kind of construction.)
The design includes a thin steel frame under the seat where the legs are mechanically fastened. The armrest is optional and fastens to the back and sides of the chair.
The X-Federation Elite Class chair comes with a solid brass armrest and leg sleeves. Must say, the contrast in materials is very interesting.
[via http://www.fastcodesign.com/1670183/using-the-secrets-of-skateboard-tech-to-build-a-better-chair and http://cubeme.com/blog/2012/06/27/x-federation-chair-by-victor-vetterlein/]