two sided pokemon cards Double-sided Base Japanese holo test prints π³π€― (the 3 on top are the front and the 3 on the bottom are the backsides of those!) These are currently on display at Double-sided "No Opaque Layer" Test
Description
They exist to compensate for an inherent weakness of pure typings

The winners received 20 copies of their card

The only way to differentiate between the two is by checking the copyright information, where the error is present

Its the experience, the excitement of what youll find, and the hope of that unique card that will complete your collection
For example, Charizard cards tend to be more expensive than many other cards simply because fans love the creature