What is a CGC comic ? - A CGC comic is basically the most trusted standard for graded comics in the comic industry . Certified Guaranty Company, also known as CGC, is a Sarasota, Florida comic book grading service. CGC is an independent member of the Certified Collectibles Group of companies. It is the first independent and impartial third party grading service for comic books.CGC comics are encased in a hard plastic display case . Inside the case they are sealed . The comics are graded by professional graders and the grade as well as details are printed on the card placed inside the case wit the comic. Sealed against tampering and the elements. A CGC is the best way to ensure your comics value for future trading .