For their fall 2024 ready-to-wear collection, Sébastien Meyer and Arnaud Vaillant, with the help of researcher and professor Ioannis Michalous, created the Aerogel Air Swipe Bag. It is a bag, basically, made of … air? What? Often referred to as “blue smoke” or “solid smoke,” Aerogel is a silicon-based solid with a spongelike, porous structure in which more than 99 percent of the volume is open space, making it a thousand times less dense than glass.