Which is why Frodo could see the faces of the Ringwraiths when he put on the Ring on Weathertop, right?
But… The Ringwraiths are given form by their clothes, meaning only their bodies are in the Unseen Realm. Yet when Bilbo, Frodo, Sam, etc., don the Ring, they vanish, clothes and all.
Does the One Ring have an extra oomph to it that the Nine do not?