I did use bag fiber to sew the seams. I didn't leave that much seam allowance because I sewed the panels right to the umbrella ribs. In fabric it would be a different process. Fabric also wouldn't stretch as much as the bag panels do. I found that when I actually attempted to leave a seam allowance the panels sagged so I had to make the last two too small so that it would pull the rest of the frame taught and there wouldn't be any visibile droop. I'm a slut for technique...when you're a craftsperson you have to be more concerned with technique than with product. If the technique isn't there the product will suck. Ask away.
I cut the fabric part off of the umbrella and then used one of the wedges to pattern the sections on. I should have written it down but every weight of plastic produces slightly different results so I just came up with a general theory and carried the fabric wedge around with me wherever I was knitting so I had something to compare to.
It would be an interesting intervention....to walk around and interact with people and talk about art and the economy. I need to figure out how to display it when it's not on a person...it's going to be in a fashion show in October but I'd like to display it conventionally...and it might be hard unless I can come up with a mannequin. Even then I think a mannequin would distract from the art. It's something I'll have to consider.