Why Print Shops Reject Raster Images (And How to Fix Yours)
Your JPG looks perfect on your phone. So why does the print shop reject it? Learn the technical reasons and how to fix your artwork.
Why They Reject Raster Files
Print shops reject JPG, PNG, and GIF because:
- •Image becomes pixelated and blurry when enlarged
- •Colors are wrong (RGB vs CMYK mismatch)
- •Resolution is too low (72 DPI vs 300+ DPI required)
- •Cannot separate into individual screen printing colors
- •Text and details don't print clearly
Raster vs Vector: What's the Difference?
🖼️ Raster Images
Made of pixels (tiny colored squares in a grid).
Examples:
JPG, PNG, GIF, BMP, TIFF, PSD
Best for:
Photos, complex images, digital display
File size:
Larger files (compressed or uncompressed)
Scaling:
Pixelates when enlarged
✨ Vector Images
Made of mathematical curves and shapes.
Examples:
AI, EPS, SVG, PDF, CDR
Best for:
Logos, illustrations, printing
File size:
Smaller files
Scaling:
Perfect quality at any size
Six Reasons Print Shops Reject Raster Files
1. Pixelation and Loss of Quality
Raster images are made of pixels. When enlarged for print, the individual pixels become visible, making the image look blurry or blocky.
Technical Details:
A 3x5 inch JPG designed for screen (72 DPI) becomes a pixelated mess at 11x14 inches for a poster. Print resolution requires 300+ DPI.
Solution:
Convert to vector using specialized software. Vectors scale infinitely without quality loss.
2. Color Space Incompatibility
Raster images are in RGB (red, green, blue) for screens. Print shops need CMYK (cyan, magenta, yellow, black) for printing presses.
Technical Details:
Automatic RGB-to-CMYK conversion often results in incorrect colors. A bright blue on screen might print as muddy purple.
Solution:
Provide files that were designed in CMYK from the start, or work with print shop to handle color conversion.
3. Resolution Requirements
Print requires much higher resolution than screens. Screen: 72 DPI. Print: 300 DPI minimum (some applications need 600+ DPI).
Technical Details:
A 1000x1000 pixel image at 72 DPI is only 13.8 x 13.8 inches. At print resolution (300 DPI), it's just 3.3 x 3.3 inches.
Solution:
Use original high-resolution files, or convert to vector which has infinite resolution.
4. Cannot Separate Colors
Screen printing requires separating artwork into individual colors (one screen per color). Raster images are impossible to separate cleanly.
Technical Details:
Color separation software struggles with raster images, often creating poor results with halos and registration issues.
Solution:
Use vector files where color separation is clean and automatic.
5. Text Quality Issues
Text in raster images appears jagged at print sizes. Anti-aliasing designed for screens makes text look fuzzy when printed.
Technical Details:
Raster text is just pixels. Print shops can't edit it, and scaling causes visible pixelation along letter edges.
Solution:
All text should be vector outlines or curves, not raster pixels.
6. File Format Limitations
JPG, PNG, GIF are raster formats. Print shops need vector formats like AI, EPS, or vector PDF.
Technical Details:
JPG is lossy compression – it discards information every time you save. PNG has transparency but is still raster.
Solution:
Use AI, EPS, or vector PDF. Convert JPG/PNG to vector format.
Visual Comparison: Raster vs Vector
When You Enlarge a Raster Image:
Original Size (Web)
Sharp
72 DPI, 500x500px – Looks good on screen
Enlarged for Print
PIXELATED
Same pixels enlarged – visible blocks
When You Enlarge a Vector Image:
Original Size (Web)
Sharp
Infinitely scalable – crisp edges
Enlarged for Print
SHARP
Same quality – perfect for printing
Understanding Resolution (DPI)
DPI stands for "Dots Per Inch." It's how we measure image resolution.
Screen Display: 72 DPI
Monitors display 72 dots per inch. Your phone screen? Roughly the same. This is why images look good on screen but print poorly.
Print Quality: 300 DPI minimum
Print shops require 300 DPI minimum. This is 4x more detail than screen resolution. High-quality print: 600 DPI.
The Math:
A 3x5 inch photo at 72 DPI = 216 x 360 pixels. At 300 DPI you need 900 x 1500 pixels. Most phone photos aren't big enough.
Quick DPI Checklist:
How to Fix Your Raster Images
Start with the Original File
If you have the original high-resolution image (camera file, PSD, AI), use that instead of a web export.
Convert to Vector Format
If you need a vector version, use image tracing software or hire a professional vectorizer.
Popular vectorization options:
- • Adobe Illustrator's Image Trace feature
- • AI-powered vectorization services
- • Professional manual tracing
- • Online vectorization tools
Ask Your Print Shop First
Contact them directly: "I have a JPG/PNG image. Can you accept it as-is, or do I need a vector version?" Many shops have solutions.
Know Your Resolution Needs
Before submitting: Check file > Properties (or Get Info on Mac) to see actual resolution. Make sure it's 300+ DPI.
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