"Binding"... why not "Bound"?

[Bebekurenai]

It's not the spiritbond I mean, it's the "item bound" I mean, that which prevents us from trading that piece once it's been used. And only the wording I'm referring to, as it should be "bound", not "binding"

[DarkmoonVael]

It depends on what is being described. Is the item bound to your character at 1% spiritbinding, making it bound to your character? Or is it still binding to be able to be converted at 100% spiritbond? The latter describes a process that is incomplete until 100%, thus it is still in the process of binding.