Four-Way Stretch vs Two-Way Stretch Engineering Guide

Understanding stretch mechanics, spandex content requirements (2-25%), ASTM D2594 testing, recovery vs stretch, and optimal applications for each type. Four-way stretch requires 8%+ spandex for both horizontal and vertical stretch, essential for leggings and yoga wear. Two-way stretch (3-8% spandex) provides horizontal stretch only, suitable for T-shirts and casual wear. Recovery is more important than maximum stretch percentage. Huada products: HD8193 (8% spandex, moderate four-way), HD8578 (20% spandex, maximum four-way), HD7928 (5% spandex, two-way).