I'm often asked about PCGS’ new Secure Plus service, which was introduced in 2010. Any collector who’s seen more than a handful of PCGS holders (also known as “slabs”) would have noticed on the a gold shield symbol on the left-hand side of some PCGS certificates (see the 1915-S Half Sovereign, right, graded PCGS MS66 Secure Plus). This symbol indicates that the coin was graded under PCGS’ Secure Plus grading service level, a premium service level introduced in 2010.
In addition to the reflective shield on the PCGS certificate (which has microprinting embedded in the design), the Secure Plus service level introduces a number of new security features. Firstly, each coin is “sniffed” by an analyser to detect cleaning, puttying, or other methods of cleaning where a substance is applied to the surface of the coin. Next, the coin’s unique “fingerprint” is taken and saved. This fingerprint is matched against similar fingerprints in the PCGS database. (A “fingerprint” in this context is a graphical or digital pattern composed by the analyser that helps to identify a coin based on the coin’s unique characteristics. Having a database of such fingerprints allows PCGS to identify resubmissions, as well as coin doctoring on previously submitted coins.) Thirdly, the coin is photographed and its image uploaded onto the PCGS website. This allows collectors to compare their PCGS-graded coin against its image in order to protect collectors against fake slabs or forgeries.
As all world (non-US) coins minted before 1965 must now be sent under the Secure Plus service level, you’ll start to see more and more of these Secure Plus slabs as time goes by. On the whole, many collectors have welcomed the fact that all Secure Plus coins have their images of the PCGS website, which is probably the most positive aspect about the new service.