The cardboard that is used on printing digipaks, wallets and jackets is generally coated on one side. The opposite side is uncoated (without any coating). Printing on the uncoated side makes the print look rough, and organic because color generally does not go on vibrant as printing on the coated side. The following are some examples:

4 panel CD digipak in reverse print

Other stock coatings available are matte coating, glossy coating and aqueous coating