I stole this idea from a similar bowl that I ran into somewhere on the net - don't remember where, but think it was a UK site - if I ever come apon the site again I'll tell you who it is.
Anyway I saw their product, thought "Neat, have to see if they import these" and forgot about it until the other day when I was in the kitchen using a cutting board/sheet, and thought "Bet I could make a bowl out of this".
I bought the cutting sheets at the grocery store (pack of 2) about a year ago, planned to trim one of them down and use it for hiking, but they never made it past the kitchen. The one I used is kind of beat up but it worked great for making my bowl.
I cut a 10 inch square out of the sheet, and then made a crease about 2 inches in on all 4 sides. I then bent a diagonal from the corners to where the first creases met. I bent the resulting triangles over against the sides of the new bowl and secured them there with paper clips.
I thought about leaving it like this, but I wasn't satisfied as the I felt the clips added unnecessary weight (and also might be lost while on the trail). So I clipped some holes high on the side with a paper punch and tied them with string.
I am thinking that when I make my final bowl out of new material I might use plastic snaps.