We have done a tremendous amount of testing on silicone membrane. We are not talking about testing where some lab can say it has x elasticity or y elongation. We have tested our membrane using real holster making conditions on actual holster molds at actual temperatures used in holster making. We have tested all thicknesses, all durometers, etc. We ran actual tests to see which membrane gave the best definition and yet was still flexible enough and durable enough to work inside vacuum formers. We then had to take into account cost. The reason for this is that there are membranes that have better “numbers” in a lab. But they either did not perform well in the vacuum former or they were just too expensive. Imagine purchasing a $100 membrane only to have it rupture after a few uses because you forgot to tape a mold corner, or sand a sharp edge on a new mold. That would be a costly mistake. We have actually seen the corners of kydex itself cut the membrane because the kydex either cooled too quickly or was not proper temperature. The membrane we ultimately selected is one that has properties that we specified and it is made for us. We know of no one else selling this membrane. It offers the most and the best value for the purpose for which it is intended without breaking the bank but it also is not the cheapest.