How to Make Contour Diapers from Prefolds
**Please read all instructions before starting. Feel free to print these out
for your personal (non-commercial) use.
You'll need a serger, or else a sewing machine that makes a wide, sturdy overcasting stitch (not just a zigzag stitch). But a serger or overlock machine would be preferable. If you do use a sewing machine, reinforce the overcast stitches with one or two lines of straight stitches just inside the overcasting (up to 3/8 inch (1 cm) from the raw edge).
For 2 dozen contour diapers, you need 24 thick prefolds (6 or more layers in the middle) or 48 thinner prefolds (4 layers in the middle).
The diapers should be prewashed and dried 2 or 3 times, if new. That is because the dimensions given below are for finished (preshrunk and stitched) diapers. I do not have dimensions to give you if you wish to cut, stitch, then wash and dry your diapers for the first time, as shrinkage can vary from fabric to fabric. However, diaper fabric is easier to work with if it's not preshrunk, because then it lies flat and smooth. If you know what percentage your new diapers will shrink, you can use that number to calculate pre-shrunk cutting and sewing dimensions. You can then cut, sew, and launder your new diapers so that they end up with approximately the finished dimensions listed below.
But you can still sew the diapers fairly easily if you need or want to go ahead and shrink them first. As you sew, you'll need to gently pull the drawn-up fabric taut in front and in back of the needle, without putting tension on the needle or feed dogs. This technique will also help keep the raw edges even as you finish them.
Below is a photo of two of our newborn-size homemade contour diapers for your reference (pardon the stains :-b ). At some point this will be replaced with one or more CAD drawings complete with dimensions.
The wider part (with side laps) goes under the baby, and the narrower part gets wrapped up and over the baby's bottom in front. Then you bring up each side lap and pin it to the front of the diaper. If you have a newborn, be sure to pin the diaper so that it does not cover baby's navel. The diaper should be snug but not too tight, so that it stays on while still keeping baby comfortable. I prefer pull-on diaper covers, but snap-on ones would work fine, too.
The diaper on the left was finished with a closer, firmer stitch than was the one on the right. Note how the larger-stitched one (dark thread) is ravelling. That was after just three months' use. To avoid this, set your machine to more stitches per inch while keeping the stitches fairly wide. Notice also how the one on the left has unequal flaps (along the bottom edge of the picture). The left hand flap is what all your flaps should look like; the right hand flap is too short and will become harder to pin as baby grows . The diaper on the right has two good flaps, but I couldn't get both flaps to lie flat for the photo (maybe I should have ironed 'em).
You've probably noticed that these newborn-size diapers lack the usual "belly button dip" (indentation to clear the navel). If you are concerned about this, go ahead and indent (curve in) the middle part of the front waistline edge 5/8 inch (1 1/2 cm) or so. I will try to remember to include the belly button dip on the CAD drawings.
Here are the finished dimensions of the contour diapers in inches, with metric to the nearest half centimeter. Note that these were measured with the fabric drawn taut (diapers normally kind of pucker up a bit after a few washings):
Newborn size: overall length: 12 1/2 inches (32 cm)
width of lap section (widest part of it): 13 inches (33 cm)
crotch width (narrowest part of diaper): 5 1/4 inches (13 1/2 cm)
width of front section (widest part of it): 6 1/2 inches (16 1/2 cm)
Regular size: overall length: 16 inches (41 cm)
lap width: 14 inches (35 1/2 cm)
crotch width: 6 inches (15 1/2 cm)
front width: 9 1/2 inches (24 cm)
Toddler size: We do not use toddler contour diapers, so these are only suggested
dimensions. You may wish to modify.
overall length: 20 inches (51 cm)
lap width: 15 inches (38 cm)
crotch width: 7 1/2 inches (19 cm)
front width: 11 inches (28 cm)
*Note: toddler size will require special, oversize prefolds available through WeeBees or Murphy's. Personally I prefer to leave the toddler size in prefold form, because older toddlers can be so, well, prolific in their output. Besides, if they have that extra amount of uncomfortable messy diaper squished between their legs, that will hopefully be greater inducement to potty training sooner. :0)
Sketch the outline with dimensions given onto a piece of cardboard the right size. Don't be too concerned if you don't get the outline "perfect" (like, exactly symmetrical) - our homemade contour diapers all have slightly different shapes, and have still worked just fine. Cut out the cardboard piece: this is your pattern.
Lay the pattern lengthwise onto the first diaper, with the thickest section of the diaper centered under the pattern and running the length of it. Take a fabric marking tool, such as a soft dark pencil or wax marker, and trace around the pattern onto the diaper. Be sure to hold the pattern down firmly. Cut the diaper with sharp fabric shears (not pinking shears), and start a stack of diapers (or better, finish the raw edge of each diaper right after you cut. Cut diapers ravel pretty fast if handled too much).
Alternatively, if you have a rotary cutter and mat, you can skip the marking step and just hold the cardboard pattern in place while you cut the diaper around it. Do this with care for your own safety, as the cutter is razor-sharp. It would probably be best not to use the cutter when the children are around, and of course, always store it safely shielded and out of their reach.
If you are making contour diapers from thinner prefolds, lay two of the cut diapers on top of each other (you may want to pin them to prevent the raw edges from shifting) then serge together at the raw edges. The thicker prefolds will each make a good contour diaper on their own.
Before you serge the real thing, make sure your serger knives are not dull (they should cut cleanly), and practice on some diaper scraps to get the thread tensions right. If you want, you can serge the diapers with colored thread for a bit of decoration (also a good idea if you have multiple babies or sizes, so you can color code the diapers). No fabric needs to be cut away as you serge the diapers; you are just finishing the raw edges that you already cut. Or, I guess you could opt to just trace the diaper outline, then serge (machine cut and overcast) without scissors-cutting first; do whatever works easiest for you. Of course if you are using a sewing machine only, you'll have to cut out the diapers first.
Again, you may or may not want to pin the raw-edged layers before serging them - it depends on your skill and/or confidence level. I personally like to use a few pins, as they help me to achieve a neater finish.
Our contour diapers were made on a 3-thread serger, but a 4-thread serger would be better, because you have that extra line of stitching to stabilize and reinforce the raw edge. If you have a 3-thread serger, use your regular sewing machine after serging to do a line of straight stitches just inside the serged edge.
The dimensions given will provide plenty of overlap for pinning and still allow for growth spurts for approximately the following ages (you'll have to "size up" sooner if your baby is especially big):
newborn size - birth through 3 to 4 months
regular size - 3 to 4 months through 2 to 2 1/2 years
toddler size - till they are potty trained
If your baby is older than newborn, may I suggest that you keep several prefolds in their original rectangular form, for use whenever you are fairly sure baby will be doing a b.m. soon (most babies tend to get pretty predictable with their b.m.s as they get older). This is because the rectangular diapers hold more than the contour ones, and so are better suited to large or messy b.m.s. You may also prefer to put baby in regular prefolds for overnight.