One idea I came up with was to take the 16″ material and cut it down its length (creating a 32″ wide sheet). Now do this to a second piece of material. Then take the two 32″ wide sheets and seal the edges together, and viola, you have a 32″ wide lay flat bag.
In my case, based on the dimensions of this hunk o cow, I believe I’d need a lay flat bag that is around 40″ wide. So in my case I’d have to seam three sheets together (two flat as described above for 32″, one folded over for another 16″, for a total of 48″ wide). The bag would need to be about 40″ long. In this case I’d end up with 3 seams, each about 40″ long.
At least in my head this seems doable. But the big question is how the heck would I do these seams?