Those $1 IKEA plastic bags at the checkout are near indestructible and great for just about anything, especially if it's heavy or otherwise awkward, but we never thought we'd see a full backpack made from them. Well, SanDiegoMitch bought three, hacked them up and built this super-light carry-all with them.
SanDiegoMitch notes that the bags are rated for up to 25kg each, and with the addition of some pieces from an old backpack and some spare fabric, he planned out the design (you can check out his plans at the link below), cut out the frame and sewed the pieces together. He made the front and back from a single piece, and went for a rolltop to try to keep the whole thing waterproof.
The shoulder straps and waist strap are from that old backpack (he found an old SeaWorld pack, which explains the matching colour), and he sewed a sleeve into the back that he could put his sleeping pad into, which serves as a kind of frame and stiffener. All told, he explains the total cost of the pack was about $US30 ($40), including all of the additional material, and he definitely spent a good bit of time on the project, but it was a lot of fun and works well. If you're interested in doing the same, hit the link below to check out more photos than you could possibly need to duplicate the project. Of course, if you'd rather just have the one SanDiegoMitch made, he's selling it (with the sleeping pad) on eBay, too.
My IKEA Backpack [SanDiegoMitch]