I used the pro treatment on my HH Mercer Triple C and it was fine on that. I started to treat the bottom of my banana Bulga cresent satchel and it did darken the leather a bit. I'm scared to use it all over that bag because although I don't mind a mild darkening of the leather, I don't want it to darken unevenly. Has anyone used it on light soft leather with good results? I'll check the bottom of the bag again today and see if it still looks darker to me. I'd really like to have some sort of protection on that leather because it's so light.