I have a natural strap i'm playing with now, no dye, no resolene, hand rub in Aussie conditioner, then hang up for a sun tan. Then repeat. Im on the 3rd coat/ sun tan, getting darker each time and more water resistant. don't know if there is a point it will stop absorbing Aussie.
I like the way Aussie makes the strap supple, flexible, I guess the cow skin will sun tan like our skin does. wonder how dark it will get?