Bubble wrap is fun to pop and great for keeping delicate stuff safe in storage and during shipping, but it seems like a huge pain in the butt to make.
Knowing nothing about manufacturing one would assume each bubble is inflated individually, but that would take way too long even with the aid of inflating machines plus it seems like a bass ackwards way to make bubble wrap. I'd always assumed they trapped and sealed air between two sheets of plastic, one flat the other covered in little bubbles, but I was wrong too.
As you can see in this How It's Made video featuring a visit the SealedAir factory the bubble is actually formed when they "vacuum the film down then trap the air" using a metal cylinder that looks like a beehive.
-Via Geeks Are Sexy