White-backed artist proofs are printed by Wizards of the Coast and are only issued to the artist. Only 50 of each card are produced. Many of my popular cards have been completely sold out long ago. The front of the cards are printed as normal but the backs are unprinted/only white. They are unique collectible items and highly sought after by some.
Each card comes signed by the artist. The prices are dictated by popularity, rarity, and inventory--as stock reduces, prices go up on remaining cards.
Set: Return to Ravnica
Card Type: Creature
Creature Type: Spirit
Casting Cost: 1
Card Text: Sacrifice Keening Apparition: Destroy target enchantment.
Oracle Text: Sacrifice Keening Apparition: Destroy target enchantment.
Flavor Text: Some souls are too damaged to be of use to the Orzhov.