CGC and/or graded books are comic books that have been professionally evaluated a trusted third-party grading service. Each book is examined for condition, authenticity, and restoration, then assigned a numerical grade from 0.5 to 10 that reflects its overall quality. Once graded, the comic is sealed in a tamper-evident, protective plastic case (often called a “slab”) with a label showing its grade, key details, and certification number.