Special black ink obscures private information. Perfect for hiding personal information on mail, documents and packages. Also useful for prescription bottles, price tags on gifts and sensitive documents. Covered information can't be easily read, scanned or copied. Works best on printed black ink. Identity Theft Secure Stamps use a special pattern to hide confidential information and is a quick and effective method of identity theft protection. Use to hide your address, social security number, account numbers or ID numbers on junk mail, magazines, catalogs, credit card offers, bills and more. This self inking stamp features a self-contained, ink pad.