I use a wide variety of clamping mechanisms for Itajime Shibori. It all depends on how thick the bundle of material I’m dyeing is once it is folded. For paper I have found folder clips to be effective. Fabric’s thicker bundle usually calls for the big boys… my faithful squeezy clamps. I even occasionally use clothespins for smaller or thinner material like silk. I’m thinking about purchasing some of those flexible strap type clamps for larger yardages of fabric sometime… maybe soon.