Or shiny side out?
Forum member "White bear" and myself have come up with a theory about foil hats working like a check valve. If you wear the foil shiny side in, then your thoughts are locked in but you are allowed to absorb info through the dull side of the foil into your brain.
Shiny side out works the opposite, your thoughts are broadcast outward but the reflective outer surface keeps exterior info from getting into your brain, like a force shield.
Something we didn't discuss but I think it's obvious so I'll share, double layer shiny facing in and shiny facing out is a total lock down. Nothing gets in, nothing gets out.
Please feel free to add information and uses for tin foil