Which of the following is not a security feature of the passport card?

The passport card incorporates several security features to protect against forgery and unauthorized access. One significant feature is the utilization of RFID (Radio-Frequency Identification), which enables electronic verification of the cardholder's identity at border crossings by allowing for contactless reading of the card.

Color shifting ink is also a security feature that adds complexity to counterfeiting attempts. This type of ink changes color when viewed from different angles, making it difficult for counterfeiters to replicate.

Invisible personal information, which may include hidden data that can only be seen under specific conditions or with specialized equipment, is another layer of security designed to protect the identity and information of the cardholder.

While microchip storage is a common feature in many modern identification documents, the passport card itself does not utilize a microchip for storage. Therefore, the correct choice reflects that microchip storage is not a feature of the passport card's security measures.