Ok, so I am am trying to make a homemade capacitor that is 4700pf and 15kv. polyester at 125 micrometers thick can withstand 15kv so were good. here is the equation i used
C=ε0 K A / D
Where C = capacitance, ε0 is epsilons constant, K = dielectric constant, A = area of aluminum foil, and D is...