| name | corner-and-edge-grading |
| description | Use when assessing the four corners and four edges. Maps what 'sharp', 'soft', 'fraying', and 'whitening' mean across grader rubrics.
|
Corner and Edge Grading
Each corner gets graded independently then averaged. Edges are walked under angled light. Black borders penalize hardest.
Corner condition tiers
| Tier | Visible at | Grade |
|---|
| Razor sharp | Perfect 90° at 10× | 10 |
| Sharp | 90° with imperceptible factory rounding | 9 |
| Slight soft | Tiny rounding at 10× | 8 |
| Visible soft | Rounding to naked eye | 7 |
| Dinged | Bent/crushed | ≤6 |
Edge defect families
- Edge chipping — tiny missing laminate flecks (black-border curse)
- Edge whitening — white cardstock showing through colored border
- Edge fraying — fiber visible (handling damage)
- Print-line on edge — vertical print line can mimic chipping
The black-border tax
Black-bordered cards (Bowman Chrome, Pokemon, modern MTG) are penalized hardest because edge whitening is most visible. A black-border 9 ≈ non-black 10 in collector value. Submit only when all four edges look pristine — most 'mint' raw black-borders grade 8.
Where this fits in the X3 empire
Used by CardPrepAI's edge-walker tool to flag black-border submissions where the upside doesn't justify the fee.
