saw one in a store..it was cheaply made and exspensive...why pay when you can use what you already have laying around and make it more personal. keep in mind this is a barebones post....it's just instructions..no photos.time varies...you can whip one out in about an hour..depending on what you're doing...sewing machines...always get the job done quicker.
here's how to make a hoodie into a bag, you can use either a zippered hoodie or a pullover. first, remove the hoodie cord. second, turn hoodie inside (zip up hoodie if it has a zipper and sew enire zipper up with quilting thread so it can't be pulled down-or bust open). third, sew the bottom of the hoodie together--using the top of the elastic banding (where it meets the sweatshirt material) for a guide---pretty much sew just above the seam on the sweater material(keep in mind you'll want to zig zag stitch on a machine--it makes them more durable). fourth, turn hoodie rightside out, secondly decide the length of the strap by inserting one sleeve into the other--the shorter the strap the more you tuck in the other sleeve. fifth, sew sleeve together on the elastic wrist band..using a square formation with an x(connecting the square corners) in the middle. Finally, enjoy. if you would like you can add patches, safty pins, pins, decals, paint, whatever to it..and if you want to you can even add a clasp to the hood(which makes the purse flap) to be able to clasp it closed--but a fair word of warning, adding the clasp always makes it look tacky. well, anyway that's the way i designed them...if you can figure out an easier and better way please let me know.
to make it into a backpack, you need to sew fabric panels into/onto the wrists of the sleeves, do not turn hoodie inside out, instead join bottom and fold elastic inside, tuck sleeve fabric panels into the bottom that you just folded in...making sure that the sleeves at least lay flat on the back(i like to place sleeves so they go in the bottome on each side..but you can put them in the center, if you want--it doesn't work as good)...pin and sew together.
okay, and alternative to sewing the zipper if you used a zipper hoodie...is not as sturdy..but it gives it the punk diy style..is just safty pin the zipper shut..doing a row of safty pins all the way up.