Centering
Upload a photo to measure left/right and top/bottom centering.
Centering looks good?
Run the numbers: enter your card’s value at each grade and see whether grading actually pays off.
Grading tools · FAQ
Pre-Grade & the Slabline engine
- What is Pre-Grade?
- Pre-Grade is Slabline's AI condition read. Upload a photo of a card and it assesses the four factors graders judge — centering, corners, edges, and surface — and returns a directional grading-readiness lean (for example, 'gem-mint candidate' or 'likely a 9'). It's a signal from one photo to help you decide whether to send a card in — not a grade, an appraisal, or a guarantee. The actual grade is always determined by the grading company.
- Why does Pre-Grade say 'unclear' instead of guessing?
- Because it is honest about its limits and it is actively getting better. Pre-Grade describes only what is visible in your photo, and it will say 'unclear' when glare, angle, or low resolution make a factor impossible to judge — rather than inventing a confident grade the way many tools do. And it improves over time: as more of the Slabline community scans cards and reports the grades those cards actually receive, the engine sharpens.
- What makes Slabline's engine different from other AI grading tools?
- Two things. First, it is hybrid: where most tools make the AI guess centering, Slabline measures centering precisely with deterministic geometry and hands that exact number to the AI — so it spends its judgment on corners, edges, and surface instead of re-guessing the one factor we can measure exactly. Second, it runs on a proprietary feedback loop: Slabline pairs the photos people scan with the real grades those cards later receive, building a labeled dataset no competitor has. Pre-Grade also lives inside the full Slabline system — real value-by-grade comps, the grading ROI calculator, your collection, and your Slabline Score — so it answers 'should I grade THIS card, given what it is worth and how protected my collection is,' not just 'what grade might this be.'
- How accurate is Pre-Grade?
- It is a readiness signal, not a verdict, and accuracy depends heavily on photo quality — a clean, straight-on, well-lit shot reads far better than a blurry or angled one. Use it to triage which raw cards are worth the grading fee, then confirm with the centering analyzer and real value-by-grade comps before you submit. Treat it as a smart gut-check, not a guarantee.
- Is it free?
- The grading ROI calculator and the centering analyzer are fully free with no signup. Pre-Grade gives you 3 AI condition scans per month free; unlimited scans, on a higher-quality model, come with an Insured plan.
- Which grading companies does it cover?
- Slabline values and reads cards graded by PSA, BGS, SGC, CGC, and TAG.