Hey all, according to CardboardConnection there are two variations for this set depending on factory set and wax pack origins:
"Variation collectors can chase after two different versions of every card. Those inserted in the factory set use white card stock, leaving backs bright. Cards from wax packs have a grey card stock on the back. Neither version carries a premium."
I am not sure if this has been discussed before somewhere, but if enough people think it should be added, maybe someone can add it. I can also try to do so once I get the checklist permissions.