Re: man made fibres. I stopped wearing cotton for riding a couple years ago, it just gets too sweaty and doesn't dry. I'd love to wear nothing but merino wool, or better still, alpaca, but that stuff is $$$. I have a bunch of polyester "microfiber" shirts, mostly cheap ones from MEC. At first, I found they made me really stinky, but not any more. Initially, I figured I had just gotten acoustomed to my own stench, but I'm pretty sure that's not it. I have no idea what would have changed, but something has. Maybe the biological critters living on your skin have to come into balance with the materials you wear on a day to day basis?