I used diaper flannel in the ones that I made for my grandson, you can order it online from Joanns. The other options they recommend besides the gauze is microfiber which is similar to towelling and I also used the terry cloth towelling also available through Joanns for the centers of the pads. There are lots of tutorials and recommendations on line for cloth diapers. Joanns also sells the waterproof material for the outside of the diaper covers.

people use old towels in between the pretty frabic flannel andfrabice like that

Hi, I made diapers from flannel. The diapers were shaped and cut with one short side on the selvedge edge. I made them in 2 sizes. When the baby had outgrown the smaller ones, I inserted them into the larger ones for more absorbency. My kids were allergic to the plastic used on the first disposable diapers that came out. Good luck with making them. By the way, my children are from ages 45 through 33 years old now. Good luck on making the diapers and finding a suitable fabric for them.