Ah the haversack, the Man-Bag of soldiers from the Revolutionary War to World War I. During the Civil War, it was the place solider's stashed personal gear. You can buy a Civil War Replica for about $15.00, or make one yourself following basic instructions.
This YouTube video also shows a simple haversack pattern, and was the spark that got me thinking about this topic in the first place. After watching the video, it occurred to me: couldn't I whip up something similar using a Tyvek Mailer?
Here's how I did just that:
Step 1: Assemble the supplies. I didn't end up using the pen. Feh, who needs to mark stuff when you can just wing it?
Step 2: Fold the envelope over. I created a nearly 5 inch flap. I'm not sure there's anything optimal about that.
Step 3: Slide the cardboard into the top of the envelope. Once in position, use a razor blade to cut one side of the envelope along the crease that you made in the fold from Step 2.
Step 4: Peel off the backing from the envelope's sticky flap and seal the envelope. There should now be one opening to the envelope: the opening you made in Step 3.
Bonus Project: Don't discard that backing strip from the envelope's flap. Instead, take a strip of Duct Tape and apply it to the glossy side. You've now got a short strip of duct tape that can be folded up and put in your wallet (or your brand new haversack). The cool part: because the glue from the Duct Tape and the backing strip are designed to play nice together, you can quickly deploy the Duct Tape with minimal effort. Try it, it's super effective. (I first learned of using tape backing to make Duct Tape easier to dispense from MeZillch's YouTube channel)
Step 5: Punch two holes near where the top of the envelope folds over.
Step 6: Thread a bit of cordage through the holes and you've got a completed haversack!
If everything went as planned, your little haversack has the same bonus featured mentioned in this video: the flap contains a pocket that will hold items when folded over. Watch the video to see what I mean. Pretty sweet, right?
So what can you do with your new creation? So much. Here's a few ideas: have your kids cover it with fun colored Duct Tape, and now they've created their own personalized bag. Use it on the trail for foraging: get it all nasty? No big deal, you can recycle it and make a new one. On the trail, you could empty it and use it as a sit pad; or fill it up with soft items and use it as a pillow. Or you could do what I did and make the world's lightest weight bike pannier:
I attached the haversack to my bike rack using a few zip ties. The result is small container, perfect for holding snacks and a few other essentials.
It won't win me any fashion contests, but it sure is functional.