Vacuum forming evacuates the air from the zone sucking the Kydex onto a mold. When the Kydex is sucked to the mould and cools it's going to take the shape with the mould. I initially stumbled on to just one of those holsters in the gun store in Gainesville and https://kydexholsterssolutions87531.get-blogging.com/27036166/indicators-on-pros-and-cons-of-kydex-holsters-you-should-know