Sew bottom panel edge with bottom edge of front panel (1/2" seam). Then sew another stitch line parallel to it but 1/4" from the edge (for reinforcement I recommend that you use seam tape to prevent fraying. You can actually make your own seam tape from a length of 1 1/4" 1.0 oz. coated nylon or any similar fabric.
Sew the rear edges of the top cover/lid to the top edge (about 2 1/2" at the top sides) of the back panel wrong side out. Refer to photo 20.
Sew side panel(s) assembly to the connected piece in item 33 inside out with 1/2" seam (this is a main seam and we have to be a bit lavish for the allowance). Apply seam tape and sew at least two more parallel stitch lines all around these main seams for durability.
Turn everything inside out and you're ready to connect the collar to the top edges. Cut the collar components according to figure 19. If the fabric you're using has a noticeably coated (i.e. a bit sticky) underside, we're going to sew the sleeve in such a way that the uncoated side is adjacent to the cord. Otherwise, you'll have a little difficulty in cinching the draw cord smooth and tight because the coated side of a fabric tends to get caught with the cord.
Fold the ends of the collar 3/8" inwards (towards the coated side) and sew. Then fold a long end (along the length) in a similar fashion and sew.
Sew collar short ends together inside out along (3/4" from the edge outline) the short ends but leave a 2 1/4" long unsewn end (at the folded edge for the drawstring sleeve). Next, fold inwards the unsewn end flat as shown in figure 20.
Now, we are ready to sew the sleeve for the drawstring. Fold the "finished" long end of the collar outwards (or towards the uncoated side) up to the 2 5/8" (from the edge outline) shown in figure 20.
Thread cord through sleeve and fasten cord lock to the ends and secure with a stop knot.
Sew collar to top edge of pack bag assembly in such a way that the cord lock seam line (it is where the collar short ends are sewn together) is aligned with the center of the back panel. Sew the connection seam again flat inside so your stuff won't get caught in an otherwise exposed seam.
Thread all webbing (shoulder strap webbing, hip belt webbing, top cover/lid webbing) through their respective buckles. Thread the lace/cord for the compression as you would lace up a shoe and then secure ends with a cord lock and a stop knot. Fold (about 3/4") and sew all strap ends so that they won't accidentally unthread by themselves. You may add a sternum strap assembly to complete your project.