Its made from sanded cedar 1" by 1"'s, folds, molds to the back of each individual (its flexible), lightweight, and cold hold a decent amount of weight. "Dr. Demolition", my brother, tried it out, and we know know it at least holds 260 lbs. A very comfortable chair- I got this one for a friends as a gift for $75 from Goodridge Lumber up in Albany, VT, my go-to place for cedar.
Something like this would be VERY easy to build- its all patterns. I've since seen many copycat looks and models- a sure sign that the design sells, works, and it wanted/people-approved.
Also, for those into rustic furniture making, here's a link to a GREAT book I recently got on the subject- some amazing photos, and VERY creative, budget-friendly ideas.....
-Derek "Deek" Diedricksen