Below are CGC Trading Cards grading standards for each numeric grade as well as information on sub-grades. A link has been provided.
Perfect 10 – A Perfect 10 is a card that has received the grade of Pristine 10 with all four sub-grades being 10. This “quad 10” is the best a card can be. It has no post-production flaws under 10x magnification in all four sub-grades.
Pristine 10 – A Pristine 10 card must have perfect centering and no evidence of any manufacturing or handling defects. Corners will appear perfect to the naked eye and Gem Mint under 10x magnification. The surface is free of print spots and should also display perfect gloss.
Gem Mint 9.5 – The card will have excellent centering and exhibit only negligible handling or manufacturing defects.
Mint 9 – The card shows at least above-average centering and only a few minor manufacturing or handling defects.
NM/Mint + 8.5 – A card with at least average-to-above-average centering. The card will show small handling defects.
NM/Mint 8 – A well-preserved card with at least average centering and small-to-moderate handling defects.
NM+ 7.5 – A well-preserved card with a moderate defect or a number of small defects.
In addition to a card’s overall grade are sub-grades; Centering, Corners, Edges and Surface.
Corners – The visual and structural integrity of the corners of the card.
Edges – The visual and structural integrity of the edges of the card.
Surface – The visual and structural integrity of the surface of the card.