Force Stool (3.5e Spell)

What is the wizard sitting on?

Man, you really need to sit down but there's no chairs. But wait, you're a spellcaster. You make a chair.

A force stool is effectively an immobile floating disk spell. It can be made colored or transparent, and breaks if more than 200 lbs per caster level is rested upon it, or if it takes more than 30 damage all at once.