I've made string blocks using phone book pages. I remove the paper before I press the blocks. I just googled the "Sediment Shield for Trenches" and found another sewing thread that says that it disintegrates or melts if ironed. It seems that it is used mostly for machine embroidery or sewers (the storm or sanitary type, not sewing). JustABitCrazy, let us know when you have tried it. You could also use Golden Threads quilting paper, comes in 12" X 20 yard rolls for about $9. I have a roll and I'll use that if I want to make larger blocks than 8.5".