what to use for waterproof liner in homemade diapers

[trinamechling]

I am making some more diapers for my 2 month old son and would like some recommendations on what to use for a waterproof liner? The ones I've made just have a 4 layer soaker and 2 additional layers of flannel so I either put a cover over it or try to catch him before he soaks everything. I also have some purchased koosies, which I love! When my DDs were little we used the prefold with the diaper pins and hoped that neither them or us got stuck during changes! I am currently knitting a wool soaker (slow going because Tucker likes to nurse constantly). My DD and I are going to go to the thrift store on Monday (50 cent day with the right color tag) and try to find some wool sweaters. Any suggestions on this?

[smudge]

A liner, like for inside the dipe, next to baby? If so, there is always fleece or microfleece, even suede cloth. All of which you can find at your friendly neighborhood fabric store....

[trinamechling]

inside the diaper, but that maybe has a waterproof side or something like that