Fabric choices affect comfort, movement, breathability, stretch, recovery, layering, and bulk consistency across the full collection. A technical T-shirt may need a moisture-wicking knit, training shorts may need quick-dry stretch woven fabric, joggers may need fabric recovery, and lightweight jackets may need breathable shell fabric. These fabrics do not need to be identical, but they should feel related in handfeel, weight, color behavior, and product role. If each SKU uses unrelated fabrics, the collection can look and feel disconnected after sampling.