Unlike normal PVC cards, which have a smooth plastic surface, signature panel cards have a special area on the back of the card that makes it easy for a cardholder to sign their name. When the card is used (most often in conjunction with a signature-authorized transaction, like a credit card), the card holder's signature can be compared with that on the back of the card to verify that it is authorized. Signature panel cards are commonly used for credit cards, library cards, and gym membership cards, but are also often seen on cards like driver licenses and student IDs.