The Artist Proof Mystery Booster Packs contains an assortment of Magic the Gathering artist proofs hand-picked by the artist:
 
Pack Options
7  Common Artist Proofs ($70 value)
7  Uncommon Artist Proofs ($140 value)
7  Rare Artist Proofs ( $210 value)
Foil Artist Proofs - 3 Common, 2 Uncommon and 2 Rare ($280 value)