HOW TO APPLIQUE A PREFOLD
1. The prefold needs to be prepped first. This is important, as the prefold will "quilt" with washing, and wreck havoc on anything you've sewn to it prior to prepping. To prep a prefold, I simply do a double cycle on hot in my washer, dry two cycles at the hottest setting in my dryer, then repeat once. If I'm going to be dyeing the prefold, I'll not repeat--it kills me to use that much water. Also make sure you've prewashed whatever fabric you're going to use for the applique. You can do this at the same time as your prefolds. I don't prewash fleece, since it won't shrink. It pills so fast, and is easier for me to work with before it has been washed.
2. Sketch your design onto paper. You can print off an image with your computer, or simply sketch it from your head. This will give you something to work off of. Make sure that the sketch or printout fits within the perimeters of the prefold. If you want the image only down the center soaker area, measure that onto your sketch to keep things the right size.
3. Apply image to applique fabric. This step will vary on what you're most comfortable doing, and the fabric you're using. It's very difficult to draw on fleece and other high-texture fabrics, so I usually freehand cut, or if the design is more complicated, pin the sketch/printout to the fabric and cut. If you are drawing/tracing/sketching onto your applique fabric, make sure to do so on the negative "wrong" side, so that the markings won't show.
4. Cut out your applique.
5. Tack applique to your prefold, in position. You can use pins, or a basting stitch (wide stitch) on your machine/hand sew. Fleece actually stays in place fairly easily without tacking down, if you're feeling lazy, which I usually am.
6. Choose your stitch. Depending on your machine and fabric, your choices will vary. For a basic satin stitch (one that leaves a thick "outline") choose a zig zag and decrease the stitch length. Choose this stitch for fabrics that fray easily, unless you want that look. For fabrics that hold their own, like fleece and other high weaves, you have more options. I like doing blanket or box stitches for visual interest, and to save thread.
7. Applique the prefold. Pick a starting point out of visual center. The eye naturally goes from top left to bottom right, so if you start your stitch at the top right or bottom left, it will be less noticable. Or something. It sounds good though, no? Go slowly and let the machine feed the fabric. There are lines on your machine, where the dogs (the little grabby guys that move up and down, pulling your fabric through the machine) and on your foot--even if it's just a thread cut out. Use those as your guide. I like to line the edge of my applique's fabric with the little line down the center of the foot, and make sure I keep straight that way. If you went with a satin/zig zag, go back over your stitches to get the desired "outline". No matter what stitch you used, backstitch at the begining and end to "seal" the stitch. Diapers [should] get washed a lot, you don't want your applique falling off.
8. Add details. I do a lot of appliques that have more stitching details than the actual applique itself. Often I use the satin stitch, for larger, more bold details. But for finer, smaller ones, I use a double straight stitch, where the machine goes over every stitch on it's own, so it looks like this: ll. It makes a thicker line than a regular straight stitch, but not near as bold as a satin stitch. Not all machines have this, so you can just choose a thicker, bolder colored thread in that case. Draw your details on in pencil, and just go over them with the machine, using the foot guides to keep your line in place. Or be crazy, and just eyeball it (i'm crazy proud of that detail work, so shamelss link to it). You can also handsew details, using embroidery floss, which is thicker than thread and will show up better.
If you want, cover up the negative side of your sewing. Flip your prefold over, see all the stitches on that side? If I've done a good job sewing, i actually like the way the negative side looks--all perfectly...negative...and stuff. But all that thread can irritate a baby's bum, and really other than showing off your flawless stitching, doesn't look so great. So...
9. Measure your center soaker area. Get the length and width, and then add 1/2 inch. Don't worry that your soaker is flawed, and the top measurement isn't the same as the bottom. I swear, they are all like that. Just go with the biggest measurement.
10. Cut out your fabric. Diaper or burp rag, you're going to want something that will absorb. Your basic cotton woven fabric will work, but isn't your best chioce. Especially if you are doing a diaper, you'll want something softer and more absorbant. Flannel and bamboo are good choices. Flannel will pill, but is easier to come by and you have more print choices, also cheaper. Avoid microfiber for a diaper. Microfiber absorbs like nobody's business, but it will also irritate the baby's skin, as it actually pulls moisture *out* of the skin. Fleece is okay and will keep moisture off the baby's bum, but will make things bulkier than they need to be. Also the pilling. Oh, the pilling!
11. Pin the fabric to the prefold. I am a sworn pinning-hater, but even I pin the fabric panel onto prefolds. Prefold soakers are irregular. Even high quality ones aren't going to be actually straight and center the length of the prfold, usually. Better to get the proper placement before sewing it down. See my opinion on picking stitches out of prefolds below. Folding 1/4 inch under as you go, try to follow the actual stitched line of the prefold soaker UNLESS you have a printed fabric, like stripes or checks, or some sort of line the eye can follow. For these, I go with the line of the fabric panel and not the soaker. You'll have a stitch line on the other side, but prefolds quilt well and assuming you use a like-colored thread, it shouldn't be too noticable. Not nearly noticible, in my opinion, as a line on the fabric that isn't followed.
12. Stitch the fabric panel on. Use a basic straight stitch, and keep as close to the edge as possible. I actually move my needle over, so as to get even closer to the edge. I like no more than 1/8th of an inch hem on my center panel. This also keeps the stitch in the presewn soaker stitch line on the opposite, showing side of the prefold. Remember to back stitch at begining and end.
13. Admire your work, you little seamstress, you. You just made your diaper stash that much more fun. And believe me, all you non cloth diaperers, diapers can be fun. No, really.
Miscellaneous information and tips...
**choose your prefold based on what you'll be using your prefold for. Cheap prefolds found at big box stores, like WalMart are good for burp rags, and not much else. If you are needing something to actually function as a diaper, you'll most likely have to go online, unless you have a local cloth diapering store in your area (ask around at natural food stores, etc) or a diaper service nearby you can purchase from. Even the so called Diaper Service Quality Gerbers (often labled "DSQ") don't work well as diapers. They're cheap and easy to come by, but not worth your money if you need them to absorb anything more than spitup. Quality prefolds are not that much more money (average $2/each) and are far superior. But again, if you are just wanting a burp rag, Gerbers are great for that.
Where I buy mine (and I do cloth diaper):
Basic, good functioning: All Together Diaper Company
Higher end, more specific sizing: Green Mountain Diaper Company
**Practice on scrap fabric. Seriously, do this. Picking out stitches from a prefold = lots of swearing and pulled fabric. Trust me on this, really. Make sure you like the stitch, that you can control the speed of your machine, and that your stitch lengths are good, all that stuff. Also, practice some turns, unless you're going to be doing all straight edges. pansy.