Orange County, CA.
All there is a endorsement statement, signed by the county registrar that it's an official copy of an original document. No raised seal.
California currently has a uniform requirement now for all vital records including birth certificates, marriage certificates, and death certificates. It has to be on a standard multicolored banknote sheet, although there are multiple suppliers.
(a) Each certified copy of a birth, death, or marriage record issued pursuant to Section 103525 shall include the date issued, the name of the issuing officer, the signature of the issuing officer, whether that is the State Registrar, local registrar, county recorder, or county clerk, or an authorized facsimile thereof, and the seal of the issuing office.
(b) All certified copies of birth, death, and marriage records issued pursuant to Section 103525 shall be printed on chemically sensitized security paper that measures 81/2 inches by 11 inches and that has the following features:
(1) Intaglio print.
(2) Latent image.
(3) Fluorescent, consecutive numbering with matching barcode.
(4) Microprint line.
(5) Prismatic printing.
(6) Watermark.
(7) Void pantograph.
(8) Fluorescent security threads.
(9) Fluorescent fibers.
(10) Any other security features deemed necessary by the State Registrar.
(c) (1) The State Registrar may suspend the use of any security feature described in subdivision (b) if necessary to enable the State Registrar, local registrar, county recorder, or county clerk to supply an applicant with a certified copy of a birth, death, or marriage record issued pursuant to Section 103525.
(2) Notwithstanding the rulemaking provisions of the Administrative Procedure Act (Chapter 3.5 (commencing with Section 11340) of Part 1 of Division 3 of Title 2 of the Government Code), the department may implement this subdivision through all-county letters or similar instructions from the State Registrar without taking regulatory action.
(d) The State Registrar, local registrars, county recorders, and county clerks shall take precautions to ensure that uniform and consistent standards are used statewide to safeguard the security paper described in subdivision (b), including, but not limited to, the following measures:
(1) Security paper shall be maintained under secure conditions so as not to be accessible to the public.
(2) A log shall be kept of all visitors allowed in the area where security paper is stored.
(3) All spoilage shall be accounted for and subsequently destroyed by shredding on the premises.
I don't believe they've issued anything without a seal in years. I've done stuff with mine before including making photocopies of our child's birth certificate and our marriage certificates. All of them show that faint "VOID" in the background when we make photocopies. I've seen the watermarks. Some use generic "PROTECTED DOCUMENT" watermarks, but the state's paper has repeated images of the state seal. I've also seen "spoilage" in action, where a clerk made a mistake and had to cross it out, note the serial number on a list, and place it in a tray for eventual shredding.
The State Department standards say that there has to be some sort of seal. This PDF document shows an image of the old abstract of birth from LA County, which should be the same layout as Orange County. I found some images of Orange County abstracts, but they have names and other personal information. I use this one because it doesn't show any names. I believe this form would not be considered acceptable by the State Dept for current passport applications. I have heard that some counties might exchange one for a current version for free, but I haven't heard of any publicizing it. They also claim that it won't be accepted by the State Dept for a passport application.
http://studyabroad.tamu.edu/StudyAbroad/media/Study-Abroad-Image/Birth-Certificate-Info-Sheet.pdf