Fleece: Wicking or Repelling?

Moisture being repelled by new fleece

Fleece is a very popular fabric used in cage liners and hammocks. It is soft, thick, and warm, and does not unravel into strings that can catch on toes. Fleece is a Polyester fabric, which is not absorbant, so it is usually used in combination with a cotton fabric or towel. The idea is that the moisture is wicked away (through the fleece) and is absorbed by a more absorbant material underneath. Your ratties stay dry and comfy on the fleece, protected from the pee trapped below. Skipping the absorbant layer underneath will cause the fleece to get smelly very quickly.

However, have you ever seen the pee bead up on top of the fleece and just sit there? This is obviously not what we want - or our poor rats will drag themselves through their own pee and get all wet, dirty, and stinky. In this case, the pee is not wicked away, it is repelled by the fleece. Why does this happen?

It turns out that new fleece is actually a bit water repellant. Thus, new liners and hammocks are prone to this beading of the pee. To avoid this, the fleece should be washed 3-4 times before use, without adding fabric softener, of course. Washing the fleece breaks down its water repellant properties and allows the pee to wick through the fleece to the absorbant layer beneath. The video below shows water being wicked away by fleece that had been washed several times (the desired result), followed by water being repelled by new fleece only washed once.

Of course, if you forget, it is not a big deal. After a few more uses, the material will eventually acquire the required number of washes and will wick properly with age.