Hi! All kites in this video are made by me and a friend of mine and they all fly steadily in the light winds. The sails are made of lightweight ripstop nylon except for the white appliqued Rokkaku which sail is made by Icarex. All kites are framed with carbon fibre rods. Hope that helps! 🙂
...and if you don't succeed on the AERIALIS Kites' website, do a google search on "how to build a rokkaku". Loads of information on the topic out there!