California Code, Government Code - GOV § 26807

The county clerk shall keep an official seal of his office for use when performing official duties other than ex officio duties which shall, when embossed, stamped, impressed or affixed to a certification, show legibly.  Such seal shall:  (a) be circular in shape;  (b) be not less than 1 1/4 inches in diameter;  (c) have in the center any words or design adopted by the county clerk;  (d) have inscribed around the central words or design, “County Clerk, _____ County, California”, inserting therein the name of the county.

Nothing contained herein shall prohibit a county clerk from continuing to use a seal of a design different than that specified herein if such seal has customarily been used prior to the effective date of this section.