Not always. A strong matching set can use different fabrics if each fabric has a clear role within the collection. Sports bras and leggings may need more recovery and support, while fitted tops or light jackets may need softer handfeel, lower bulk, or easier layering. The key is to keep handfeel, color presentation, stretch behavior, and visual language aligned. Using one fabric everywhere may look simple, but it can also weaken support, comfort, or layering performance.