so what's this??

so here we have two Braves teamcards from the 1980 Topps set.

Front One
Front Two (btw, I LOVE the red pants)

The back of Front Two looks like this... just like the other cards in the set...

the back of Front One looks like this...

it is also a lot thinner card stock. It's not from any food packaging, and it's not OPC.... what is it from?

One of you who collected baseball in 1980 will know the answer I'm sure. Help a Canuck out...