One can build a Capacitor out of any conducting material as long as one also has an insulator between the conductors. For example aluminum foil sandwiched between glass plates, plastic, paper, stretch food wrap, plastic bag material, wax paper, paper soaked in oil, etc. will all work. It can be rolled into a tube or not.
The formula for determining capacitance is: C=(0.224KA/d)(n-1)
How to Make Capacitors
