X3 on the self liner.. It works great. I've also use the lid of a egg carton and hatched them in there and all the shell and stuff stayed in there. Be careful using paper towels are anything type of light weight paper. Someone mentioned on the forum that they used it and a piece of it got sucked up in the fan.
i dont want to use paper towels heard to many bad stories about it such as drying out the membrains for those who sat the eggs on the paper towels ect. mines a still air incubator. for humidity i heard useing a jar with a sponge works well