Questions and answers
About measuring centering, grading references and how the app handles your photos.
Card centering and grading FAQ
Can CenterMint measure a card in a sleeve, top loader or graded slab?
Automatic measurement works on raw cards only. A sleeve, top loader or slab adds its own edges and glare, so the app would be measuring plastic instead of the card. When it detects a sleeve, it tells you and switches to manual alignment, where you line up the four card edges yourself. For the most accurate result, take the card out and rescan.
How accurate is the centering measurement?
It depends on the photo and on the lines you confirm. Small shifts matter: with 3 mm borders on each side, going from 50/50 to 55/45 moves the artwork only 0.3 mm. CenterMint fits gold and silver borders edge by edge at sub-pixel level and flags the lines it is unsure about, but it does not claim a single accuracy percentage. Check flagged lines in the loupe and retake blurry or glary photos.
What centering does a PSA 10 need?
PSA’s published Gem Mint 10 guideline is approximately 55/45 or better on the front and 75/25 or better on the back. PSA 9 is approximately 60/40 on the front and 90/10 on the back. BGS and CGC publish their own scales, and some figures apply only to certain card categories. Centering is one of several criteria, so good centering alone does not guarantee a grade. Check the official pages before submitting.
How does Worth Grading? decide whether a card is worth grading?
For each grade it calculates: extra money = (graded price − raw price) × (1 − selling fee) − grading fee. The selling fee is paid whether you sell raw or graded, so only the price difference is reduced by it. The break-even top-grade price is raw price + grading fee ÷ (1 − selling fee). If even the second grade (such as PSA 9) makes money, the answer is worth grading; if only the top grade pays, it depends on corners and surface; if no grade pays, or centering rules out the grade that pays, it is not worth grading. The app never estimates the chance of a 10.
Does CenterMint look up eBay or other market prices?
No. The app does not connect to eBay or any price service and does not guess prices. You enter recent sold prices yourself, and they are saved on your device for that card. In Japan, buttons open Mercari sold listings and Yahoo! Auctions closed listings for the card name and number.
Does CenterMint check corners, edges and surface?
No. Corner & Edge Close-ups crop the four corners and four edges from your original photo at full resolution so you can inspect them yourself. The app does not score them, and a phone photo can miss tiny flaws, so check doubtful spots under a loupe and bright light.
What is free and what needs Pro?
Free: centering measurement at full resolution, the loupe, the guided line check, PSA/BGS/CGC reference comparison, one batch of up to 5 cards, and the pre-grading check (Worth Grading? and close-ups) on one card of your choice. Pro adds those pre-grading tools for every card, the Submission Log, batch scanning, the decision assistant with a submission checklist PDF, CSV and 4K exports, presets and no ads.
Is CenterMint affiliated with PSA, BGS or CGC?
No. CenterMint is an independent app. Its centering references follow the companies’ published standards for comparison only, and an actual grade can differ.
Are my card photos private?
Measurement runs on your iPhone without an account. Photos are uploaded only if you opt in to correction sharing (off by default) or accept the one-time batch learning notice, which you can decline. Prices and the Submission Log stay on the device.