I use corrugated wrap in my PVC cages, and have found it to be humidity neutral... Before I used it (was using butchers paper or paper towels) my humidity stayed around 60% without misting, and now that I use it my humidity is still 60% without misting.
* I do live in a humid area, and my cages hold humidity in very well
** I haven't used the cage liners yet, but will give them a try once my current roll of corrugated wrap runs out.