Aluminum foil will be pervious to light, super light?
Boxed milk is a lot of paper boxes, there is a layer of aluminum, there is a layer of plastic, this box visible light, I'm afraid it is not easy to pass through, X ray should be able to.
The micron sized aluminum foil can be rolled directly, and the nanometer aluminum foil can deposit an aluminum layer on the organic substrate by vapor deposition, and then dissolve the substrate with organic solvent
Any foil can be pervious to light until it is thin to a certain extent
