The black parts of the inflatable back band and the associated attachment points are scored into the fabric piece labeled “Seat +” and around the packraft’s floor fabric. Baffle D is scored into the sheet of colored tube fabric.
Note: if you ordered your kit before October, 2024, these parts are not pre-scored in your kit, but you can still make your backrest into a back band. You’ll just have to cut out the straps and attachment point shapes from the scrap tube and floor fabric. You can retrofit an existing backrest by cutting off the side seams and inserting straps before welding the sides together again.