Because it was what I had on hand, I have used a lower-grade (non-laminated) pig feed bag from our local feed and fertilizer manufacturer rather than one of the slick, pretty Purina chicken feed bags that sell for $8-12 on eBay and Etsy when transformed into tote bags.
1. Clean it up. Cut off or remove the stitching at either end of the bag, as well as any paper labels. For the actual washing of the bag I would recommend a warm, soapy washrag or sponge. For the purposes of experimentation (read: shits and giggles) I threw this bag into the washing machine with a heavy duty load (Matt’s filthy work pants and a pair of throw rugs) but it disappointingly unraveled about 3 inches on one end, and wrapped itself around one of the suspender studs on Matt’s jeans. No, I did not put it in the dryer.
2. Flatten it and take measurements. Decide from which end you will be taking chunks for handles so that your logo stays centered (You will be taking one 3-inch strip for handles. You will also lose about 1-1/2 inches off of both the top and bottom to hemming and some of the bottom of the bag will be underneath the load and won’t be visible.). I ironed my bag lightly with a dry iron set to nylon (the lowest setting on my iron). This is probably not necessary for the fancier, heavier bags.
3. Sew the creases. This step wasn’t included on most tutorials I found online, but I wanted to keep the folds in my lighter “fabric” crisp so that it would neatly fold when not in use. I topstitched the creases, just as far from the edge as my presser foot is wide. In retrospect, I wish I had done this last – not first. I turned the bag inside-out to sew the “inside” crease and right-side-out to sew the creases that point out. (I hope that makes sense).
4. With the bag right-side-out and the side creases flattened (not tucked in as they will be when the bag is finished) sew across the bottom of the bag, leaving about a 1/2 inch seam allowance. Then flip the bag inside-out and sew across the bottom again, this time about with about a 3/4 to 1 inch seam allowance. This creates a French seam that prevents fraying – and this stuff really really wants to fray. Leave no edge unhemmed!
5. Here comes another bit that’s difficult to explain (hence the sudden image-heaviness). Turn the bag right-side-out and put thumb and forefinger of one hand in the side crease while tugging on the inside corner with the other hand (inside the bag).
Tug on the corner inside and push out with the thumb and forefinger of the other hand on the outside of the bag and you should create a nice pair of right angles.
Squash this flat and pin it against the bottom of the bag.
Repeat on the other side. (This might be one of those things, like I come across all the time when I’m knitting, where it makes no sense at all until you actually do it.) Tug on one corner of each end to create nice sharp line from corner to corner along the front and back of the bag. Pin this down, too.
You can, in theory, run a line of stitching all the way around the bottom of the bag, but I’m not that great with the physics of sewing machines, so I did the ends and then the sides. If I haven’t completely confused you then you should have a nice rectangular bottom on your bag now.
6. Fold the top of the bag down about 1/2 an inch and then again about 1 inch. Topstitch at 3/4 inch and 1/4 inch from the new top of the bag to secure the hem.
7. Cut your handle strip into two pieces of equal length. Fold each one in 1/4 to 1/2 inch on all sides and then in half (lengthwise). Topstitch close to the edge around the whole shebang. Figure out where you want your handles to attach (My bag’s front and back are 14 inches wide. I put my handles on four inches from either side and four inches from each other.) Topstitch a square around the end of each handle to attach it firmly to the body of the bag.
8. Do a little dance!
If this sounds like an ass-pain don’t you worry: there’s bijillions of different ways to accomplish pretty much the same thing. Just Google it or go fart around on Craftster (itself a fascinating timesuck) and you’ll find one that’s perfect for you.