In the first part of this series, the official site asked some experts on the best material they could use to create the Saiyan Armor allowing it to stretch as they transform into giant apes. The conclusion they got in part 1 was that woven polyurethane, but the problem with that is once it stretches past a certain point, the material becomes see through and in part 2 they talk about ways to prevent this.
The gist of it is that woven polyurethane probably isnt the best way to make this and either a gel version of the material or a combination of it with the newly discovered polyrotaxane would be better. They go through the pros and cons of the gel version, which unlike woven material has no meshes so sweat and heat have no way of escaping, which isnt ideal for high exertion activities like combat. They also mention auxetic fibers and how that can be used to make clothing via 3D printers. In the end they conclude a combination of the two P’s would be the best material, but I think science hasn’t matched fiction in this field yet so we will have to wait to see. You can read the whole interview here!