I did these as a birthday present for my husband. He is very picky about seating, but he said these were very comfortable! I used 1x4 oak for the headers and pine for the rest. After reading others' concerns about the support dowel, I decided to do the following:
1. Drill a 3/4" hole halfway through each 1x2 support with a 1/4" hole continuing the rest of the way through to the outward facing side of each
2. I glued a 1/4" dowel into one 1x2, pushing the dowel as flush as possible to the outer edge of the 1x2. I then slid a 3/4" hollow steel tube onto the wood dowel, and into the 3/4" hole in the 1x2.
3. Finally glued the other end of the wooden dowel into the other 1x2 (which forces the steel tube to nest into the 3/4" hole in the 1x2) and trimmed the excess dowel flush. The steel tube acts as the support, and the 1/4" wood dowel simply holds it all together. Did that make any sense?
If you can possibly avoid paying full price on the fabric, DO! That alone accounts for 70% of this project's total cost!