The 40L Mountain Flyer Ultralight Backpack is a great place to start or continue your ultralight DIY backpack journey. The backpack is light-weight and simple to make. If made correctly it is extremely durable on the trail.

This build features the classic Mountain Flyer silhouette, shock cord compressible side pockets, y-top strap, hip belt, front and side lash points, front mesh pocket with buckle closure, padded back panel, and whatever else you want to add/remove for your personal needs.

You can have confidence in using the core pieces of this pattern while modifying pockets, lash points, etc. as you go. Have some fun, will ya?!

Looking for videos to guide you through the build? Check out our ! (The 34L Video Lesson has the majority of the same build instructions as the 40L backpack. An updated lesson will be coming soon!)