I have found a few times that I have wanted to have a backpack skin on one character after using it on another, for example using the Quaggan skin on one, then needing a fractal backpack instead. I was thinking it would be good if tradeable white/blue backpieces could be added so people could do the usual transmute to blue to account bind trick. It would make sense for Anet too, as you use two fine transmute stones this way.