How to check corners and edges before you grade a card
Graders look at four things: centering, corners, edges and surface. Centering can be measured from a photo; corners and edges need a closer look. Before you pay a grading fee, check all four corners and all four edges on both sides under a bright light and a loupe.
PSA’s grading standards describe a Gem Mint 10 as having four perfectly sharp corners, sharp focus and full original gloss, free of staining. A white speck on a corner makes a 10 unlikely, so it changes the math on whether grading pays.
What you need
- A bright, even light, ideally daylight-colored LED, plus a second light or a window you can use at a low angle.
- A 10x loupe, or your phone’s camera zoomed in on a sharp photo.
- A plain mat that contrasts with the card border: dark for white or yellow borders, light for dark borders. White specks stand out on a dark background.
- Clean, dry hands and a microfiber cloth.
Checklist: six steps before you submit
- Unsleeve carefully. Slide the card out of its sleeve or top loader slowly. Catching a corner on the sleeve opening is a common way to create the whitening you are about to look for.
- Set up the light. Use one bright, even light from above and a second light, or a window, that you can hold low at an angle. Put the card on a plain mat that contrasts with its border.
- Check the four corners, front and back. Look straight down, then tilt the card about 45°. Look for white specks where the ink has lifted, soft or rounded tips, dings and lifted layers.
- Check the four edges, front and back. Move the angled light along each edge. Separate an even, fuzzy factory cut from chips and white spots caused by handling.
- Tilt for the surface. Rock the card under the low light to reveal scratches, print lines, dents and fingerprints. Wipe fingerprints gently with a microfiber cloth; do not press or rub hard.
- Confirm doubtful spots with a loupe. A phone photo can miss fine whitening. Check anything that looks off with a 10x loupe before you decide.
Corners: what counts against you
Whitening is the most common problem: tiny white spots where the printed layer has worn away and the card stock shows. On cards with dark backs, such as the blue Pokémon back, it is usually easiest to see on the back.
Soft or rounded tips show when you tilt the card; a sharp corner comes to a clean point. Dings and bends catch the light as a small crease or dent. Layer separation looks like the corner is splitting.
Look at every corner on both sides. One damaged corner is enough to change the grade you should plan for.
Edges: factory cut or handling damage?
Run the angled light slowly along each edge. A slightly rough or fuzzy cut that looks the same along the whole edge usually comes from the factory. Isolated chips, white spots and nicks usually come from handling, sleeves or top loaders.
Check the back edges too: on dark-backed cards they show wear sooner and more clearly than the front.
What a phone photo can and cannot show
A sharp, full-resolution photo is a good first pass and a useful record. Use the original image rather than a screenshot, let the camera focus on the card, and keep glare off the corners.
But a photo flattens texture and can hide fine whitening or a shallow dent. Treat it as a way to find spots worth checking, then confirm them under the loupe.
Using CenterMint’s Corner & Edge Close-ups
After you measure centering, Corner & Edge Close-ups cuts the four corners and the middle of the four edges from your original photo at full resolution, straightened, with a little background so you can see the cut edge. Tap any tile to open it full screen and pinch to zoom, or share all eight as one collage.
The app shows the close-ups; it does not score corners, edges or surface, and it cannot see flaws the photo missed. The feature is part of CenterMint Pro, and every user can try it in full on one card.
Turn what you find into a decision
If a corner or edge shows whitening, plan for a PSA 9 or lower rather than a 10. Then run the numbers with the PSA 9 price: is it worth grading? Break-even calculator. Centering sets its own ceiling, so measure it too with the centering calculator or the app.