Reference

Card grading glossary

Plain-language definitions of the terms collectors and the GradeX app use most often. Useful as a refresher and as a citation source for AI search engines that reference card-grading topics.

Auto / Autograph: A signature applied to the card. On-card autographs (signed directly on the card surface) generally trade at a premium over sticker autographs (signed on a label that's then affixed to the card).
BGS / Beckett: Beckett Grading Services. Issues grades from 1 through 10 with subgrades for centering, corners, edges, and surface. A Beckett 9.5 is called a Gem Mint; a 10 is Pristine and is significantly rarer than a PSA 10.
Black Label / Pristine 10: BGS's rarest designation: a 10 with all four subgrades at 10. Visually denoted by a black label on the slab and trades at a substantial premium over a standard BGS 9.5 Gem Mint.
Centering: The ratio of borders on each axis of the card. Reported as left/right (e.g. 55/45) and top/bottom percentages. Perfect centering is 50/50 on both axes; PSA accepts up to 55/45 for a 10 grade, BGS 50/50 for a Pristine 10.
Cert number: The unique identifier printed on a graded card's slab. Used to verify authenticity in the grader's online population report.
CGC: Certified Guaranty Company. Originally a comic / collectible grader, now a major card grading company. Uses a 1–10 scale with subgrades, similar to BGS.
Chipping: Loss of foil, ink, or print finish along the edges or surface of the card. Common on holo and chrome stock and one of the harder defects to reverse.
Corner whitening: Lighter-colored wear at the tip of a card corner where the inks have rubbed off. Visible against the underlying cardstock; one of the most common defects on lightly-handled cards.
Defect map: GradeX's visualisation of every imperfection the AI found, overlaid on the front and back card images with colored markers. Each marker is tappable to see the AI's description and severity rating.
Edge nick: A small chip out of the card's edge — usually from contact with a hard surface. Heavier than print chipping; impacts the edges subgrade specifically.
Gem Mint: PSA / CGC 10 or BGS 9.5. The grade most collectors aspire to and where most modern card value sits. Defined by sharp corners, clean surface, even centering, and no manufacturing defects.
Grade boundary: The numeric threshold between two grades — e.g. 9.0 vs 9.5. Cards close to a boundary are flagged as borderline and trigger self-consistency reruns in GradeX so the prediction reflects genuine model uncertainty.
Holo / Holographic: A card finish with a metallic, light-reflecting layer that produces a rainbow shimmer. Common on Pokemon and Topps Chrome lines. More prone to scratches and silvering than matte stock.
Lookup population (pop): How many copies of a specific card-grade combination exist in a grader's database. A low pop relative to demand drives premiums.
Numbered (parallel): A card explicitly limited to a fixed print run — e.g. /99, /25, /1. Rarity is stamped on the card. Numbered parallels typically trade at a premium proportional to the print run.
Off-center: Centering far enough off 50/50 to drop a card a grade tier. A 60/40 horizontal centering will typically cap a card at PSA 9 / BGS 8.5.
Parallel: A variant printing of a base card with a distinct visual treatment — e.g. Refractor, Prism, Mojo, Disco, Wave. Each parallel has its own population and price tier.
Pop report: A grader's public list of how many of each card / grade combination they've certified. PSA and BGS both publish them; collectors use them to assess scarcity.
Print line: A faint line on the card surface from the printing process. Often visible only at angle and frequently affects the surface subgrade.
PSA: Professional Sports Authenticator. The largest and oldest major card grader. Issues grades 1–10 with half-grade increments above 8 and a label-only Gem Mint at 10.
Raw card: An ungraded card. Trades at a discount to its graded equivalents because the buyer is taking on grading risk.
Refractor: A specific holographic finish from Topps. Variants include Prizms (Panini's analogue), X-Fractors, Atomic Refractors, etc. Each has subtle visual differences relevant to identification and grading.
Rookie card / RC: A player's first official licensed card. Often the most valuable card of a player's career, especially for stars. RC indicators vary by manufacturer.
Self-consistency reruns: GradeX's technique of re-running borderline grading calls 2 extra times at higher temperature and taking the median. Reduces the impact of any single ambiguous evaluation.
SGC: Sportscard Guaranty Company. Smaller than PSA but well-regarded for vintage. Uses a 1–10 scale with the iconic black-and-white tuxedo slab.
Silvering: Wear along the edges of a holo card where the foil layer is showing through. Distinct from edge chipping; common on heavily-handled vintage holos.
Slab: The hard plastic case a graded card lives inside. Tamper-evident; cracking it cracks the grade.
Subgrades: The four component scores that go into a BGS or CGC overall grade: centering, corners, edges, surface. Each is rated 1–10 in half-point increments.
Surface defect: Anything affecting the card face: scratches, fingerprints, print lines, indents, scuffs, fading. Distinct from corner or edge defects.
TAG / TAG Grading: An automated grading service that issues a numeric score from 1–1000 plus a letter grade. Aims to remove subjective human judgment from the process.
Vault: GradeX's term for the user's saved card collection — purchase price, target sell price, defect annotations, price history, and a direct route to list on the marketplace.