Since the release of Cryptopunks and Bored Apes, most blue chip NFT collections have used the same recurring concept for their creative baseline: An illustrated portrait (also known as a PFP, for profile picture or picture for proof) altered into a few thousand variants made slightly different by using a random distribution of customization layers. These unique traits of various rarity levels can affect face shapes, eyes, skins, outfits, accessories, backgrounds, etc.