The upper of the Spira model is dyed in delicate EarthColors® natural colors from Wildling's partner Archroma. Archroma has almost completely replaced the petroleum content with plant-based waste materials in its dyes, typically 70 to 100% in commercially available dyes.
The upper material consists of a mix of cotton and hemp. Both fibers naturally regulate temperature and moisture so that our feet are well-ventilated. The inner lining is also made from organically produced cotton from Cotonea, a brand that stands for transparent supply chains, organic cultivation, and fair trade.