I was working in the yard in the rain with temps around 40 F the other day and decided to do an experiment.

I wore the following garments (listed from skin out):
(1) polar fleece pullover
(2) cotton T shirt
(3) somewhat leaky rain jacket-coated-non breathable

After about two hours of fairly light work I went inside the house, removed the garments and inspected them. The polar fleece was dry to the touch. The T shirt was soaked and had approximately doubled its weight from 8 ounces to 16 ounces. The rain jacket was wet on the inside and outside.

I was comfortably warm while working due to the dryness of the polar fleece. I assume the cotton T shirt had kept it dry by absorbing the sweat coming from my body and the leaking from the rain.

This worked for a couple of hours. If I had stayed out longer I'm guessing the T shirt would have stopped its magic because it was pretty saturated. Switching to a dry T shirt, however, would have allowed me to go for another stint with warmth provided by the dry polar fleece.

So how can I use this to make me more comfortable while backpacking? I'm not sure. I don't carry any cotton clothing when backpacking. It's usually wet and cold when I'm hiking in the mountains of Washington and cotton is heavy and cold and agonizingly slow to dry when wet. The idea of carrying a a 1 lb wet T shirt around for a few days doesn't appeal to me and I'd probably add a lb of some other quicker drying clothing instead.

Can you think of any lightweight backpacking applications from this wet T-shirt experiment?