Today I was sewing up some natural fiber fitteds for a woman interesting in trying some basic fitteds (who had been using prefolds and synthetics before and preferred the prefolds). So, I'll use this opportunity to talk about soaker shapes.
When I first started sewing cloth diapers, I stuck to the very simple long rectangle and long rounded corner rectangles. Like how the typical pocket diaper inserts are. They work fine, but they leave that funny middle bulge on the butt and don't utilize the maximum absorbency and fit for the size of diaper.
So, then I switch to contoured newborn soaker my newborn fitteds, AIOs, and AI2s, and a long-fold mostly rectangular soaker with only a wider contoured top for my M-L and OS diapers.
Here is a newborn fitted with the newborn contour snap-in soaker.
Here is one of my multi-wing fitted diapers sewn up with the medium wing length.
Inside (organic bamboo velour inner)
Here is the soaker snapped in.
For this one, I did the two-layer petal soaker with the snap only through the bottom petal.
Here is just the soaker petals. They are far from perfect...
Opened to show both layers and the snap.
Here is a MEDIUM sized Fold-In Fitted.
For this, I used the contoured soaker shape from my LARGE Sized Pocket AIO to give the middle extra absorbency. It also provides visual guides for your leg-elastic casings.
Here, you can see how the form gives an excellent guide for sewing your casing seams.
Here is just the cut out cotton fleece before I stitched it into the body.
Templates can be downloaded here: http://prefold2fitted.blogspot.com/2012/10/online-free-downloads.html