Definition: Passivetex fabric is a type of synthetic material used to create lightweight, breathable garments for athletic wear. It's typically made from recycled polyester with an inner lining of cotton or elastane, resulting in soft, stretchy fabric that feels good on the skin and breathes well. Passivetex fibers are known for their low environmental impact, as they're produced using water-based dyes and require less energy to produce than traditional synthetic fabrics.