Vivobarefoot used the latest edition of the Outdoor Retailer Winter Market, which was held in Denver on Nov. 8-11, to present its range of plant-based shoes. The range comprises the Primus Bio, which uses a plant-based polymer – a product based on industrial field corn – in its sole and upper, with 60 percent of the outsole and 30 percent of the upper being made from DuPont's Susterra propanediol-based Bio-TPU. The result is described as the least petroleum-reliant performance shoe in the world. Other models include the Ultra Bio and the Stealth III Bio, both of which feature material derived from algae, in partnership with Bloom, a company that uses algae biomass from freshwater sources to make foams that can be used for footwear. Also, the collection comprises the Magna Trail Bio and the Primus Trail Bio, which use a natural rubber compound that the brand says is extracted from trees in the Amazon rain forest.