Alcantara is a man made material that's used mostly in sport car interiors such as Porche and Lamborghini. It's characteristics are abrasive, stain and water resistance, flame retardant and very durable.
I found it perfectly suited for straps. It's resistance to abrasion is a big plus as the strap still looks new after months of testing (black strap in the picture is my personal strap. Looks new).
The fact that it's artificial fiber, it will not get rotten by constant contact with water and sweat. I wear the strap in shower, pool and steam room and it dries quite fast.
All and all, I highly recommend giving the Alcantara strap a try. You will love it.