Using the 8-inch zipper, pin the A side of ExIn and ExO to one edge. The zipper should be between the two fabrics with the zip facing the ExO piece. The “right” side of the fabric should be facing each other with the wrong side facing out. Sew along edge. Flip fabric pieces to make zipper visible. Optional: Sew along edge to flatten fabric.
Repeat above on the opposite side of the zipper using the other ExIn and ExO fabric.
Move the two ExO pieces of fabric so that they are facing each other. Align the B, D, and E edges.
For the interior fabric on the outside pocket, align the edges with the inside pocket – D should match with K2, B should match with K1, and E should match with L2. Sew along these edges.
Fold the corners of the ExIn pieces, fold so C1 and C2 are flat against each other on both sides. This flattening should also flatten the J1 and J2 edges. The C and J edges should only touch the adjacent side from the same pieces of fabric. Sew shut.
For the two ExO pieces, sew along lines B and the outside of line D leaving a 2 inch gap. Flatten C1 and C2 so they are parallel with each other. Sew shut.
Flip bag inside out and gently push out corners. Sew the remaining of the D line on the ExO pieces of fabric.