I’ve done it plenty of times when ad hoc testing lack of connectivity on WiFi or BT devices and the microwave is too far to walk. Works a treat. Though I generally used Cliff Bar wrappers (our devices were small, and I don’t like chips/crisps).

Though by about the sixth round of golf I’d be making myself a clean, permanent phone jacket out of Reflectix or something.

do these snack bags have metalic material in them strictly for the graphics to have gloss and shine? What purpose does it serve?

Porosity. The metallic material is to cut down on air transfer.

I love being surprised, I would have never guessed that. Very cool. Porosity of bicycle inner tubes is an inconvenient problem for me and others, I don't suppose a metalic layer would work in that application however with the expansion and all. Cool to know though.

You could make it being crumpled and that way being flexible. The expansion is not that bad.