I didn't take many pictures while making the "Macpack" because I was basically pulling the design out of the air and I didn't want to keep pausing to take a bunch of pictures because I'd lose my train of thought. Anyways beforehand I picked up a used, quality backpack from a thrift shop and tore out the straps and carry-loop.
I copied the way the zipper was installed in the store-bought backpack.
Um, this is a picture of one of the body pieces with a piece of the front flap thing.
And...here's the finished deal. To me there's not much to say about it, its got a front, back, and a "loop" of fabric including the piece with the zipper that goes around the sides. The straps and carry-loop were installed in the same place as they were were on the store-bought backpack. There's a piece of heavy-duty stiffener (same as I used in the head's neck) in the back piece, and every piece of fabric is doubled, and its all double-stitched for durability. I haven't done it yet but I'll be putting in some Velcro on the flap, and also I think I'll need some heavy-duty snaps in the sides to give the thing more shape. I ought to have put the stiffener in the bottom, but I think I can still get some in there.