The fabric remind me of a softer burlap. It's sturdy, however the cushion got creases and flattens easily even though it has a nice firm feel as you first sit (and I'm only 117 pounds!). It will return to shape a few minutes later though. 
We did have to have a replacement backing sent. When we opened the box, there was a couple of indentations in the fabric that did not return to shape after letting it sit for about 2 days. Wayfair is AWESOME about replacement parts for each time I've had to do so! They come fast!