print-lab-validator

name	print-lab-validator
description	Validates product images meet print lab requirements before listing. Checks DPI, color space, file format, and resolution against listed print sizes.
version	1.0.0

Print Lab Validator

Don't list a 60x40 print from a 12-megapixel source.

Purpose

Validates that product images can actually be printed at the sizes listed on the product page. Catches resolution mismatches, color space issues, and format problems before a customer orders.

When to Fire

• On /lab command
• When adding or modifying product pages
• When listing new print sizes
• As part of pre-publish-checklist (Gate 1 enhancement)

DPI Requirements

Print Size → Minimum Resolution

Max Print Size	Min DPI	Min Pixels (Long Edge)
8x10	300	3000
12x16	300	4800
16x24	300	7200
20x30	240	7200
24x36	200	7200
30x40	150	6000
40x60	150	9000
60x40 (landscape)	150	9000

Rule of Thumb

• Gallery prints (up to 24"): 300 DPI minimum
• Statement pieces (24-40"): 200 DPI acceptable
• Mural size (40"+): 150 DPI acceptable (viewing distance compensates)

Color Space

Context	Required	Notes
Print lab submission	Adobe RGB or ProPhoto RGB	Wider gamut for print
Web display	sRGB	Standard for screens
Product page images	sRGB (converted) + original preserved	WebP for web, TIFF/PNG for lab

File Format

Purpose	Format	Notes
Lab submission	TIFF (uncompressed) or PNG	No JPEG for final print files
Web display	WebP (primary), JPEG (fallback)	WebP at 85% quality
Archive/source	RAW or TIFF	Never delete the source

Validation Checks

1. Resolution vs. listed sizes: For each print size listed on the product page, verify the source image has sufficient pixels
2. Color space: Web images should be sRGB. Verify no accidental Adobe RGB images on the web (colors will look wrong)
3. WebP versions exist: Every product image should have a .webp version for web display
4. Aspect ratio match: Listed sizes should match the image's actual aspect ratio (or note cropping)
5. File size sanity: Web images >2MB should be flagged for optimization

Validation Report

## Print Lab Validation — [product name]

**Source image:** [filename]
**Resolution:** [width x height] px
**Color space:** [sRGB / Adobe RGB / ProPhoto]

### Size Validation
| Listed Size | Required Pixels | Actual | DPI at Size | Status |
|-------------|----------------|--------|-------------|--------|
| 12x8 | 3600x2400 | 7200x4800 | 600 | ✅ |
| 24x16 | 7200x4800 | 7200x4800 | 300 | ✅ |
| 60x40 | 9000x6000 | 7200x4800 | 120 | ❌ TOO SMALL |

### Format Check
- [ ] WebP version exists
- [ ] TIFF/PNG source available for lab
- [ ] Web image is sRGB

### Overall: [PASS / FAIL — reasons]

Integration

• pre-publish-checklist — runs as part of the publish gate
• standards — product standards may reference image requirements
• careful-not-clever — don't guess resolution. Check the actual file.

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Soli Deo Gloria — The print quality is part of the art.