I had some old pants and wanted a new backpack so this seemed like a logical next step. Everything you see here except for the straps came from the pants themselves.
Pants may vary, so unfortunately I can't give a single pattern that will work for every pair. Therefore I recommend continuing only if you're somewhat comfortable improvising with a sewing machine or if you're ok changing route halfway for a drawstring pantsknapsack (not as catchy, I know).
The only thing you'll definitely need are some pants and a needle and thread, but I strongly recommend:
- A seam ripper, rotary cutter, cutting board, and ruler
- A sturdy sewing machine
- Cotton webbing for straps, with two plastic strap adjusters
Step 1: Disassemble Pants
This can be tedious but also fun and cathartic. Start by ripping the inseam and side seams. you can take out the hem too and remove the waistband and zipper but I'd leave everything else intact for now. Make sure you don't rip out any seams you might want to keep.
Step 2: Make a Plan
Most pants aren't one size fits all, and neither are PANTSPACKS. Take a look at how much fabric you have and come up with plan of attack. A brief measuring tape survey of the backpacks I had on hand revealed average dimensions of 18" high x 12" wide x 7" deep. Decide what sized rectangle you like and see if you can make that happen with the amount of fabric you have. It might look like a lot of fabric now, but once you start putting things together it disappears quickly.
Also look at what elements from the pants you might like to retain in the final product. Use this to help guide your layout decisions.
Step 3: Start Cutting
Once you've decided what parts of the pants will make which faces of the bag, go ahead and start cutting out those rectangles. Don't spend too much time with your back horizontal or an Abigail might decide to sleep on it.
PSA: BE SURE TO INCLUDE A SEAM ALLOWANCE, and I recommend at least a solid 1/2" to give yourself some wiggle room and enough space for sturdy seams.
Step 4: Pin and Then Baste It Together
Remember - this is haute couture. Take your time with this to make sure everything comes together the way you'd imagined. Expect to do lots of basting, ripping, and re-trying. Some things to consider before moving on:
-Am I happy with the size?
-How does it look on my back?
-Will it fit all my favorite goodies?
If so, carry on!
Step 5: Figure Out the Straps
I used 1" cotton webbing and to my surprise, I didn't end up needing more padding on the shoulders. I think this is because the cotton is thicker and softer, so doesn't cut in to you the way those mean polyester straps do.
For the top attachment, I made some triangles out of fabric to reinforce the attachment. At the bottom, I used squares that were sewn in at an angle so they naturally point out 45 degrees.
Rip out a bit of the seams on the bags where you want the straps to attach - aren't you glad you basted them first? And sew those puppies in. Don't hold back - use the reinforcements to go over them multiple times.
Step 6: Sew, Sew, Sew!
Once you're satisfied with the layout, size, and straps, flip your bag inside-out and reinforce every seam you can find! Who knows what precious articles you'll be toting around, so don't be shy and give that machine a run for its money.This w
Step 7: The Closure
It was a challenge to create a closure with just the pants materials, and next time I'll probably allow myself another zipper or something here. If you want to stick with pants-only like I did, here's what I came up with.
The waistband forms a loop that the buttonhole can slide on, which folds down and buttons to the front part of the bag. Also consider using some extra fabric inside to make an elastic "sphincter" if you will (sorry - if you can think of a better descriptor I will gladly change it) which I've prototyped in muslin here.
I ended up using my bag for a couple days with the closure basted on while I fine tuned it. Remember this is a work in progress, so feel free to test things until you're happy with them!
Step 8: Tote!
Tote your old belongings with newfound pride because you have your very own PANTSPACK and nobody can stop you.
If you didn't make it this far, fear not! You can selvage any pantastrophe by turning it into a drawstring bag - instructable to come!