What does 60/40 centering mean?
It means one border takes 60% of the total border on that axis and the opposite border 40%. That is 10% off centre, which scores 7 on Gradeon's centering scale.
Article
Oct 21, 2026
Centering Isn't an Opinion: the 4 Numbers That Decide It
Centering comes down to four border widths: left, right, top and bottom. How they turn into ratios like 55/45, how Gradeon scores them, and why graders still disagree.
By the Gradeon Team · Updated
Centering comes down to four numbers: the width of the left, right, top and bottom borders. Opposite borders become two ratios, and the worse one sets the centering sub-grade.
Centering is the one part of a grade you can measure rather than judge. Here is how the four numbers work, and how Gradeon turns them into a score.
1. The left border
The border is the strip between the physical edge of the card and the printed frame of the artwork. Gradeon measures its width on the left side first. On its own, one width means nothing; it only matters compared with the right.
2. The right border
Together, left and right give the first ratio: the share of the total horizontal border on each side. If the left border is 5.2 mm and the right is 4.8 mm, the ratio is 52/48. Each pair always adds up to 100.
3. The top border
The top border works the same way, compared with the bottom.
4. The bottom border
Top and bottom give the second ratio, for example 49/51. Gradeon writes both together as a centering ratio: 52/48 | 49/51. A perfectly centred card is 50/50 | 50/50.
How do the four numbers become a sub-grade?
Gradeon takes the deviation, how far each ratio is from 50/50, and uses the worse of the two axes. 52/48 | 49/51 is 2% off centre. The deviation reads straight off the centering scale:
Deviation | Example ratio | Centering sub-grade |
|---|---|---|
≤ 2% | 50/50 – 52/48 | 10 |
≤ 5% | 53/47 – 55/45 | 9 |
≤ 8% | 56/44 – 58/42 | 8 |
≤ 12% | 59/41 – 62/38 | 7 |
≤ 16% | 63/37 – 66/34 | 6 |
≤ 20% | 67/33 – 70/30 | 5 |
Beyond 20%, the sub-grade drops one point for every further 5%: 75/25 scores 4, 80/20 scores 3. The same scale applies to the front and the back.
What does a 55/45 card score?
55/45 is 5% off centre, which scores 9 on centering in Gradeon. Centering counts for 15% of each side's grade, so a 55/45 card with otherwise clean corners, edges and surface can still pre-grade very well. Off-centring hurts most when it is severe, because the cap rule holds a side to its weakest area plus 1.0: a 62/38 back scores 7 on centering and caps that side at 8.
Why do graders disagree about centering?
Because the measurement depends on where you put the edges. Finding the printed border on a full-art card, or the physical edge of a dark card on a dark background, involves judgement. Each grading company also publishes its own tolerances, which can differ between front and back, so the same card can meet one company's standard and miss another's. Gradeon applies one scale to both sides.
Why does Gradeon ask you to confirm centering?
Automatic border detection is good but not perfect, and centering is the one thing you can verify with your own eyes. After every Full Grade, the app shows the eight pins, four on the card's corners and four on the printed border. If they line up, one tap confirms. If not, you drag them and the ratios and grade update live. The grade is not final, and cannot be shared, until both sides are confirmed.
For how centering combines with the other three areas, read Card Grading, Explained.
Measure your card's centering
Run a Full Grade and Gradeon measures all four borders on both sides, then lets you confirm every pin.
Frequently asked questions
Is 55/45 centering good?
Yes. 55/45 is 5% off centre, which scores 9 on centering in Gradeon.
Is the back of the card graded for centering too?
Yes. Gradeon measures and scores centering on both sides with the same scale, and asks you to confirm both.