The short version
A 3:2 image naturally matches sizes such as 4×6 and 12×18. A 4×5 or 8×10 print uses 4:5 and requires a substantial side crop in portrait orientation; 5×7 requires a smaller crop. Set print ratio first, position the crop, then calculate output pixels and bleed.
What matters most
- Print dimensions with different ratios cannot all use the same full-bleed crop.
- 8×10 and 16×20 share 4:5.
- Bleed and lab trimming can remove additional edge content.
How to apply it
- Read the full-resolution 3:2 source dimensions.
- Select the exact paper or opening ratio.
- Calculate and position the largest matching crop.
- Add printer-specified bleed outside the final trim where required.
- Check post-crop pixels against desired DPI and proof the final file.
Reference table
| Ratio | Crop from 6000 × 4000 landscape | 300-DPI output | |
|---|---|---|---|
| 4×6 | 2:3 portrait / 3:2 landscape | No ratio crop | 1200 × 1800 |
| 5×7 | 5:7 | 2857 × 4000 portrait | 1500 × 2100 |
| 8×10 | 4:5 | 3200 × 4000 portrait | 2400 × 3000 |
| 16×20 | 4:5 | 3200 × 4000 portrait | 4800 × 6000 |
Use exact dimensions and units in production notes; familiar labels can describe more than one standard.
Identify the print ratio family
Print names describe physical dimensions, and their shapes differ. 4×6 and 12×18 are 3:2; 8×10 and 16×20 are 4:5; 5×7 is its own 5:7 ratio. Matching inches alone without simplifying the ratio hides the required crop.
Orientation swaps ratio order but not shape. A portrait 8×10 is 4:5, while landscape is 5:4. Rotate the source correctly before comparing and use the actual lab opening if a mat covers part of the nominal print.
- Simplify width and height.
- Account for orientation.
- Check mat opening as well as paper size.
Calculate crops from the full-resolution source
For a 6000 × 4000 landscape 3:2 source, a centered 5:7 portrait crop using full height is about 2857 × 4000. A 4:5 portrait crop is 3200 × 4000. Position can shift, but these maximum crop dimensions do not.
After selecting the crop, compare retained pixels with output. An 8×10 at 300 PPI needs 2400 × 3000, which fits comfortably within 3200 × 4000. A 16×20 at 300 PPI needs 4800 × 6000, requiring enlargement from that same crop.
- Calculate crop before PPI.
- Use retained dimensions for quality decisions.
- Center only when composition supports it.
Allow for bleed and trim tolerance
Borderless printing commonly enlarges or trims slightly so no white edge appears. Exact behavior varies by lab and product. Keep faces, signatures and borders away from the trim edge, and follow the printer's supplied template when it conflicts with a generic ratio.
If a precise border must remain even, avoid uncontrolled borderless enlargement. Use a larger paper, include an intentional margin or request a workflow that respects exact image boundaries. Order a proof before a large run.
- Use the provider's template.
- Protect critical edge content.
- Proof designs with visible borders.
Export the print derivative once
Complete color and retouching on the master, apply the approved crop nondestructively, then resize and sharpen for the final print dimensions. Export in the color space and file format requested by the lab without repeatedly reopening lossy copies.
Verify inches, pixels, orientation and embedded profile. DPI metadata alone does not create detail; the actual pixel dimensions divided by print inches determine supplied pixel density.
Common mistakes to avoid
- Assuming 8×10 has the same ratio as 4×6.
- Calculating DPI from original pixels instead of post-crop pixels.
- Placing borders or signatures inside trim risk.
- Letting a lab auto-crop without reviewing composition.
Continue with the right tool
Use a calculator to check the numbers against your own source and destination instead of relying on a generic preset.
Related guides
Cropping vs Resizing an Image: What Actually Changes?
Understand how cropping and resizing affect composition, aspect ratio, pixel dimensions and quality so you can choose the correct operation.
Image cropping and print preparationHow to Crop an Image to an Aspect Ratio Without Stretching
Calculate and position an exact aspect-ratio crop while preserving natural proportions, important content and enough pixels for output.
Image cropping and print preparationHow Much of an Image Will Be Lost When Cropping?
Calculate crop dimensions, removed pixels and percentage area when fitting one image aspect ratio into another without distortion.
Frequently asked questions
How much width is lost from 3:2 to 4:5 portrait?
A 6000 × 4000 landscape source rotated conceptually for portrait retains a 3200 × 4000 crop, removing 46.7% of the original width.
Does 5×7 exactly match a common camera ratio?
No. It is 5:7, between several common capture shapes.
Can borders prevent cropping?
Yes. Fit the complete image inside the paper and use the remaining area as intentional border.
Is 300 DPI always required?
No. It is a strong close-view target; source detail, print process, size and viewing distance matter.