Hiking Backpack Main Fabric vs Accent Fabric: What’s the Difference?

https://outdoorsfaqs.com/hiking-backpack-main-fabric-vs-accent-fabric/
Hiking and backpacking backpacks typically have three different external fabrics used in their construction: main, accent, and bottom fabric. The bottom fabric meaning should be self-evident, but the other two may be confusing. The main fabric is the primary material that forms the pack’s body and core structure. On the other side, accent fabrics serve as secondary materials that can add aesthetic appeal or reinforce high-stress areas. Ultralight packs frequently have only one fabric used.