Been playing with Tyvek which Hilda kindly sent to me, as I can't source any locally. I painted 4 pieces of tyvek in different colours using acrylic dabbers. Once dry I stacked them on top of each other, firstly sewing around the edges to secure them and then I carried on with a random pattern. I then pinned the tyvek to a piece of material to keep it flat and then I pinned that piece of material to another piece!!! I placed everything on top of a heat resistant sheet and started to melt the tyvek with a heat gun.
If you don't pin the tyvek down it will all shrivel into nothing.