Simple RAW thread for 3.5 #31. By now, your question has probably been answered.

[Lekgolo137]

Q41
If you are not on the Material Plane (nor the Astral Plane), you can not become ethereal, because the Ethereal Plane is not connected to elsewhere.

What if a creature native to the Ethereal Plane casts Planar Bubble? Could you become ethereal on the area covered by the spell?

What about the same case, but with Shadow Conjuration and the Plane of Shadow instead?

If the answers are negative, there is any way to achieve this (to become ethereal or cast shadow conjuration outside of the Material/Ethereal/Shadow/Astral Planes?