Guild Wars 2

I don’t know how they really work. Lets say I used them on an exotic level 80 weapon. Would I still be able to transmute those skins with fine transmutation stones onto another weapon? Or is it a one time use?

One time use. You click the item and then select the weapon to apply it too. It’s like transmuting but you don’t mess with the stats. You can transmute the skins, but like all transmutations, you lose the weapon.