My [limited] Understanding a Faraday cage is that the holes block the signal if the holes are significantly smaller than the signal wavelength.
So when I wrap my cell phone in the foam (isolating it from the next layer) and wrapping it entirely into aluminum foil, why doesn't the signal block? And it doesn't.
Does the film have to be grounded? Makes the cage [foil] Do you have to be a certain thickness based on the wavelength that has to be blocked?
Questioning thoughts (especially my wife, but now too) would like to know.
Thanks.