If you’re a writer, storyteller, or self-publisher, you’ve likely faced this question: “I’ve carefully edited my book, and now I need beautiful images for the cover or illustrations—where do I find them?”
In the past, your options were straightforward: you could draw them yourself, hire an artist, or download stock images—free or paid—from various websites.
But now, there’s a new option: letting AI generate images for you. This brings up a new question: are AI-generated images suitable for printing?
Technically, the answer is simple: yes—as long as the resolution is high enough (300 DPI) and you convert them to CMYK. Of course, you’ll still need to handle the non-printing issues yourself—things like copyright or the AI giving characters too many fingers.
Understanding Resolution (DPI)
DPI (dots per inch) refers to the number of dots printed per inch. The formula for calculating image resolution is:
Resolution (DPI)=Image pixels / Print size in inches
Or, to determine the required pixel dimensions for printing:
Image pixels=Print size in inches × Standard print DPI
Example:
– To print a 4×4 inch image at 300 DPI → 4×300 = 1200 pixels per side → 1200×1200 px
– To print an 8.5×11 inch image at 300 DPI → 8.5×300 = 2550, 11×300 = 3300 → 2550×3300 px
Quick tip: Always make sure your print dimensions are in inches when doing this calculation.
You can also use a simple program to calculate the required pixel size: just enter your desired print dimensions in inches, and it will automatically give you the pixel dimensions for 300 DPI.
AI Image Generation and Sizes
Most mainstream AI image generators produce images in the following ranges:
- Common resolutions: Default image sizes are usually 512×512 px or 1024×1024 px. Some tools support larger sizes like 2048×2048 px or 4096×4096 px. Examples: Stable Diffusion, MidJourney.
- Maximum resolutions: Paid or advanced services may offer 4K images (~3840×2160 px) or higher. Professional AI generators can even go beyond 6000×6000 px, and tools like Let’s Enhance can upscale images to hundreds of megapixels.
- Upscaling solutions: You can generate a smaller image and use AI upscaling software (e.g., Topaz Gigapixel, Let’s Enhance) to enlarge it several times while retaining detail.
- Custom dimensions: Many AI generators allow you to set specific aspect ratios or image sizes to match your printing needs.
In short: basic AI-generated images range from 512×512 px to 1024×1024 px. Advanced or paid tools can generate 4096×4096 px or higher.
Recommended Printing Sizes for AI-Generated Images for Books
Below is a quick reference table for how AI-generated images translate to print, assuming 300 DPI:
| AI Image Size | Recommended DPI | Suitable Print Size | Notes |
|---|---|---|---|
| 512×512 px | 300 | ~1.7×1.7 inch | Small prints or icons |
| 1024×1024 px | 300 | ~3.4×3.4 inch | Small illustrations |
| 1792×1024 px | 300 | ~6×3.4 inch | Horizontal illustrations |
| 2048×2048 px | 300 | ~6.8×6.8 inch | Medium illustrations |
| 3840×2160 px | 300 | ~12.8×7.2 inch | Large illustrations or covers |
| 4096×4096 px | 300 | ~13.6×13.6 inch | Large prints or cover art |
Color Mode: RGB vs CMYK
One thing to keep in mind: AI-generated images are usually in RGB color mode, which looks great on screens but doesn’t always match printed colors. For printing, you should convert the image to CMYK color mode, ideally using a standard profile like Japan Color 2001 Coated. This helps minimize color differences between what you see on your computer and the final printed product.
Conclusion: Printing AI-Generated Images
Technically, AI-generated images are suitable for printing—as long as the resolution is high enough (300 DPI) and you convert them from RGB to CMYK for accurate colors. Whether you generate high-res images directly or upscale smaller ones, printers treat AI images the same as any other image. If you cannot create images yourself, hire a professional, or purchase stock images, AI can be a viable alternative. Just remember, non-printing issues like copyright or AI quirks are still your responsibility.
