Card Grading Glossary

Every grading term, explained simply

A plain-English glossary of the terms PSA, BGS, and CGC use to grade trading cards. Many of these dimensions map directly to the 16 zones CardGrade Intelligence (CGI) inspects when it predicts your grade in about 60 seconds.

Core Terms

Condition Pillars

CGI Inspection Zones

CGI Inspection Points

The Terms

12 terms every collector should know

From centering ratios to the BGS Black Label, these are the words that decide what a card is worth.

Centering: Centering measures how evenly the image is framed by the borders, expressed as left/right and top/bottom ratios such as 55/45 or 60/40. It is one of the four core grading pillars and the single most common reason a card misses a perfect grade. CardGrade Intelligence measures centering across multiple border zones on both faces.
Gem Mint: Gem Mint is the near-perfect tier, scored as a 10 by PSA, CGC, and SGC or 9.5 by BGS. A Gem Mint card shows sharp corners, clean edges, a flawless surface, and tight centering, typically 55/45 or better. Only the slightest flaw, visible under magnification, separates it from a true Pristine grade.
Subgrade: A subgrade is an individual score for each condition pillar: centering, corners, edges, and surface. BGS prints all four subgrades on its label, while PSA and CGC usually report a single overall grade. Subgrades reveal exactly why a card landed where it did. CGI returns a subgrade-style breakdown across its 16 inspection zones.
Slab: A slab is the sealed, tamper-evident plastic case a card is encapsulated in after professional grading. The label inside displays the grade, card details, and a unique certification number. Slabbing protects the card, authenticates it, and locks the assigned grade. Resale value almost always references the slabbed grade rather than the raw card.
Pop Report: A population report, or pop report, is a grading company database showing how many copies of a specific card exist at each grade. Collectors use pop reports to gauge scarcity: a low population at the top grade signals rarity and can sharply increase value. PSA, BGS, and CGC each publish their own pop reports.
Whitening: Whitening is the pale fraying that appears along edges and corners when the cardstock core shows through worn print layers. It is most visible on dark-bordered cards and is a frequent grade-limiter. Even minor whitening can drop a card from Gem Mint to Mint. CGI flags whitening within its dedicated edge and corner zones.
Print Lines: Print lines are thin streaks or bands left on a card during the factory printing process, running across the surface. Because they are manufacturing defects rather than handling damage, graders weigh them differently, but visible print lines still reduce the surface score. They are easiest to spot by tilting a card under raking light.
Surface: Surface is the condition pillar covering the entire front and back face: scratches, scuffs, print defects, stains, indentations, and holo or foil integrity. Surface flaws are often the hardest to see without angled light. CGI maps surface defects across multiple zones on both faces using specialized lighting and relief analysis.
Edges: Edges is the condition pillar evaluating all four cut sides of a card for chipping, whitening, dents, dings, and rough or uneven cuts. Edge wear is common on handled cards and on dark borders where flaws stand out. CGI inspects each edge as its own zone, so a single nicked side is scored independently.
Corners: Corners is the condition pillar judging the sharpness and integrity of all four corners. Graders look for fraying, soft fuzzing, rounding, and bends, often under magnification. A single touched corner can cap an otherwise flawless card below Gem Mint. CGI evaluates each of the four corners as a separate zone across the front and back.
PSA 10: PSA 10 is the top grade on the Professional Sports Authenticator scale, labeled Gem Mint. It requires sharp corners, clean edges, a flawless surface, and centering of roughly 55/45 or better on the front. PSA 10 is the most recognized benchmark in the hobby and typically commands the highest resale premium for a given card.
BGS Black Label (Pristine): A BGS Black Label is a Beckett Pristine 10 earned only when all four subgrades, centering, corners, edges, and surface, are a perfect 10. It is far rarer than a standard BGS 9.5 Gem Mint and is printed on a distinctive black label. For elite cards, a Black Label can exceed even a PSA 10 in value.

CardGrade Intelligence (CGI)

These terms map to 16 inspection zones

Centering, corners, edges, and surface are the four pillars every grader uses. CardGrade Intelligence breaks them into 16 zones and 47 inspection points to deliver AI grade predictions that mirror how PSA, BGS & CGC grade, in about 60 seconds. You also get the market value at every grade and a shareable public grade certificate.

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These terms map to 16 inspection zones

Every grading term, explained simply

12 terms every collector should know

Centering

Gem Mint

Subgrade

Slab

Pop Report

Whitening

Print Lines

Surface

Edges

Corners

PSA 10

BGS Black Label (Pristine)

These terms map to 16 inspection zones

Pre-grade your cards before PSA does

Every grading term, explained simply

12 terms every collector should know

Centering

Gem Mint

Subgrade

Slab

Pop Report

Whitening

Print Lines

Surface

Edges

Corners

PSA 10

BGS Black Label (Pristine)

These terms map to 16 inspection zones

Pre-grade your cards before PSA does