Originally, the dirty diapers came back in grocery sacks, but since I have a bunch of PUL in my fabric stash from making my own diaper covers, I figured I should just whip up a bunch of reusable wet bags for that purpose. The first batch I made were barely big enough to hold the 6-8 diapers I get back a day, so I made BIGGER ones and now the small ones are good for the onesies that get messy at lunch or dirty diaper covers.
To make your own, you will need: about 1/4 yard of PUL, 12 inch zipper (or 1" longer than the short side of your bag, if you are changing the dimensions), thread and your machine. A walking foot and zipper foot are HIGHLY recommended, though, you know, not required. Did you all know you can get PUL at Joanne's these days? It's craziness!
Cut your PUL fabric to 11" x 26" (or whatever size you like. This size will hold over 10 regular, full-of-*stuff*-diapers.)
Then, using your zipper foot, seam close and to the right of the zipper teeth.
Next, close your zipper. Placing your work on a flat surface, and with right sides together, line up the long sides of the bag. Align the no-teeth side of the zipper with the unsewn raw edge of the fabric and pin in place. Be careful not to catch the other side of the fabric here.
Pin and sew! Now, the two ends of the fabric should be connected by the zipper. Close the zipper and open it up the fabric tube to the right side and using both your hands as you sew (I know, tricky!) pull the fabric taut on either side of the zipper. Top seaming holds the fabric away from the zipper teeth. (Still have the zipper foot for this step.) Gah, you can totally see my wonky seam there! Darn contrasting thread!
I like to offset my zipper by about 2 inches, but you can do however much or little as you like. Either way, lay your work on a flat surface, and with right sides together, carefully line up the long sides so that the zipper is straight and parallel/perpendicular to the sides and the fabric is as flat as possible. Pin in place. (Notice, I trimmed the zipper at this step.)
Now, and this is super important, open up the zipper--at least a few inches--so you can turn the bag later. The added bonus is that with the big zipper pull out of the way, you can sew a nice straight seam.
Pin the zipper ends close together.
For sewing the sides, I've found that it's about a billion times easier to deal with the "sticky" PUL if I switch to the walking foot. Seriously. Go out and buy a cheap walking foot and it will be your best friend for all kinds of situations. I bought this one to go with my old Singer and it works just fine on my new (non-serger) Baby Lock, and I paid under $20 for it.
Then, sew up the sides. Even with the walking foot, it will take a little effort to keep the fabric straight and moving evenly through the machine, so don't be afraid to grab hold of the fabric with your left hand while you sew. Turn the bag inside out.
You're done! Aren't you glad all that work is going to be used for holding dirty diapers? (If it makes you feel better, it can also hold wet swimsuits, too :)
Here's the finished product, with a similar one holding a day's worth of the goods. Sweet!