How to Use Rectifi

Your complete guide to card centering analysis

1. Getting Started

Rectifi makes it easy to check the centering of any trading card, whether you're evaluating a card before submitting to a grading service or just curious about how well-centered your pulls are.

1
No account required. You can start scanning immediately, no sign-up needed. All users get unlimited standard scans and 1 free Pro Scan per day for perspective-corrected analysis. Your most recent analysis is always accessible from the home screen.
2
Open Rectifi and you'll land on the Scan tab, the main hub for analyzing cards.
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Choose your source: tap the camera button to take a live photo, or the photo library button to pick an existing image.

2. Taking a Photo

For best results, place your card on a contrasting flat surface. You don't need to hold your phone perfectly flat or directly above the card. Rectifi automatically corrects for perspective.

When you open the camera, Rectifi will automatically:

💡 Tip: You'll see a status indicator at the top of the camera showing the current state: "Searching," "Hold Steady," or "Focusing." Just hold still and Rectifi handles the rest.

After capturing, Rectifi will automatically correct the perspective of your photo so the card appears perfectly flat, even if you held the phone at an angle.

3. Choosing a Method

After straightening, Rectifi shows you a before/after comparison and gives you three choices for how to proceed:

✓
Straightened Image. Proceed with the perspective-corrected image to fine-tune borders and analyze centering. This is the recommended choice for most cards.
✋
Manual Corners. Place four corner handles on the card edges yourself for maximum precision. Great for sleeved cards, dark borders, or busy backgrounds.
📷
Original Image. Skip perspective correction and analyze the image as-is. Use this when you've already cropped or scanned the card flat.

You can also set a default method in Settings so Rectifi automatically uses your preferred approach without showing the options page each time.

💡 Tip: If auto-detection doesn't find your card, Rectifi will let you know and give you the option to try Manual Corners or Original Image instead.

4. Adjusting Borders

After straightening, you'll see the Border Adjustment screen. This is where you fine-tune exactly where the card's borders are. Rectifi shows two sets of handles:

Drag any handle to adjust its position. The centering is calculated from the gap between these two borders on all four sides.

As you adjust, a floating info bar at the top shows your live centering ratios and grade qualifications — so you can see the impact of each adjustment in real time.

💡 Tip: Pinch to zoom in for precise placement. The handles support push-border behavior: dragging the inner border past the outer will push the outer one along, so you can't accidentally create invalid measurements.

Use the Front / Back toggle in the toolbar to specify which side of the card you're analyzing. When you're satisfied, tap Continue to see your results.

5. Manual Corners

For maximum precision, you can place the four corners of the card manually. This is also useful when auto-detection struggles with dark-bordered cards, foil cards, or busy backgrounds.

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Drag each corner handle to match the four corners of your card. The handles are offset from the actual corner so your finger doesn't cover the placement point.
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Pinch to zoom in for precise placement. The drag sensitivity automatically increases when you're zoomed in.
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Tap Analyze and Rectifi will warp the image using your corner positions and take you to border adjustment.

6. Reading Your Results

The results screen shows two key measurements:

Lower numbers closer to 50/50 mean better centering. Most grading services look at the worst ratio between L/R and T/B when assigning a centering grade.

From the results screen you can:

💡 Tip: Use the Front / Back toggle to switch which side you're evaluating. Back centering uses more lenient thresholds at most grading services, so the same ratios may qualify for a higher grade on the back than the front.

Below the ratios, you'll see grade qualification badges from the major grading services.

7. Grading Standards

Rectifi shows what centering grade your card would qualify for under three major grading services:

Each service has different centering thresholds, and they evaluate front and back differently. The badges update automatically when you toggle between Front and Back.

⚠️ Note: Rectifi's results are for reference only. Actual grading depends on many factors beyond centering, including corners, edges, surface quality, and the grader's professional judgment. Use Rectifi to get a quick sense of where your card stands, not as a guarantee of any particular grade.

8. Scan History

Signed-in Pro subscribers get cloud-synced scan history. Every analysis is automatically saved so you can review past scans anytime.

All users can access their most recent scan from the home screen. Upgrade to Pro for full history.

9. Accounts & Tiers

Rectifi offers two tiers:

🆓
Free. No account needed. Unlimited standard scans plus 1 free Pro Scan per day for perspective-corrected analysis. Your last analysis is always accessible from the home screen.
⭐
Rectifi Pro. Unlimited Pro Scans, full cloud-synced scan history, front/back scan pairing, and more.

Pro Scan limits reset at midnight Pacific time. Your remaining Pro Scans are shown on the home screen.

10. Settings & Preferences

The Settings tab lets you customize how Rectifi works:

Under Preferences, you can fine-tune:

Ready to try it?

Download Rectifi and check the centering of your first card in seconds.

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