Drop Stitch Technology
Let's get this out of the way from the beginning, the "drop stitch" use in GentleTents has nothing to do with knitting, or even conventional sewing! Drop-stitch technology is a relatively recent development and is manufactured in a limited number of locations around the world. It allows lightweight inflatable structures to take on rigid architectural shapes, such as airplane wings, at an air pressure that is much lower than the tires of your automobile. Around the world, most popular use of drop stitch is inflatable boats and, especially, stand-up paddle boards. You may have seen people using a long paddle while standing on what looks like a fiberglass surfboard, but you may not have realized that most of those paddle boards are actually inflatables built with drop stitch technology.
Drop stitch is what keeps the base of GentleTent Roof-Top Tents from bulging in the middle like a balloon. It's also what allows those same bases to be rigid enough to hold your weight as a cantilever as you climb into the tent. In a drop stitch fabric, the structural layer consists of a top layer and a bottom layer separated by a space (and a shape) that is dependent on the ultimate product. between the top and bottom layers, hundreds or even thousands of fine polyester threads of exacting length are "dropped" from the top layer and precisely sewn to the bottom layer using a large automated mechanism. The edge material is then attached and various laminating processes are used to finish the product and make it air tight.
If you are interested in further online study of drop-stitch technology, a particularly useful resource is on the website of Northwest River Supplies at https://www.nrs.com/tech_talk/dropstitch.asp