I was just going to ask the same thing. I have two sets of twin size flannel sheets I am cutting up to make fitteds. I wasn't sure how many layers I would need to have. I was comparing the flannel to birdseye pique(sp?) and I think flannel is just a little bit thicker, but I'm not sure about absorbancy. I was planning on doing 2 full inner layers, 1 full outer layer, 6 layers for the soaker, and then a 3 layer doubler. There are for a NB size, so I may decide that 6 layers is getting too thick.
I'll be paying attention to see if that is too much or too little.
Jen