California Code, Government Code - GOV § 8207

A notary public shall provide and keep an official seal, which shall clearly show, when embossed, stamped, impressed or affixed to a document, the name of the notary, the State Seal, the words “Notary Public,” and the name of the county wherein the bond and oath of office are filed, and the date the notary public's commission expires.  The seal of every notary public commissioned on or after January 1, 1992, shall contain the sequential identification number assigned to the notary and the sequential identification number assigned to the manufacturer or vendor.  The notary public shall authenticate with the official seal all official acts.

A notary public shall not use the official notarial seal except for the purpose of carrying out the duties and responsibilities as set forth in this chapter.  A notary public shall not use the title “notary public” except for the purpose of rendering notarial service.

The seal of every notary public shall be affixed by a seal press or stamp that will print or emboss a seal which legibly reproduces under photographic methods the required elements of the seal.  The seal may be circular not over two inches in diameter, or may be a rectangular form of not more than one inch in width by two and one-half inches in length, with a serrated or milled edged border, and shall contain the information required by this section.

The seal shall be kept in a locked and secured area, under the direct and exclusive control of the notary.  Failure to secure the seal shall be cause for the Secretary of State to take administrative action against the commission held by the notary public pursuant to Section 8214.1.

The official seal of a notary public is the exclusive property of that notary public, and shall not be surrendered to an employer upon the termination of employment, whether or not the employer paid for the seal, or to any other person.  The notary, or his or her representative, shall destroy or deface the seal upon termination, resignation, or revocation of the notary's commission.

This section shall become operative on January 1, 1992.