How to Format Images and Graphics Inside Your Book
For images inside a book, resolution and placement matter most. For print, images must be at least 300 DPI at the size they'll appear, in the right color mode, and placed so they sit near the text that references them with sensible margins. For ebook, images should be good-resolution but web-optimized (not huge files), centered, sized to fit small screens, and given alt text for accessibility — and because ebooks reflow, images sit inline rather than being precisely positioned. Never bake important text into an image, and for complex charts or tables consider a high-resolution image or fixed-layout. Here's how to handle images in both formats.
Text is forgiving; images are not. A picture that looks fine on your screen can print blurry, overflow an e-reader, or blow up your file size. Whether it's photos, diagrams, charts or decorative graphics, images are where a lot of book layouts go wrong. Here's how to format them properly.
Images in print: resolution is everything
- 300 DPI minimum, at the final printed size. An image that's 300 DPI shrunk small is fine; the same file blown up large becomes blurry. Resolution is relative to how big it prints.
- Right color mode. Print uses CMYK color; screens use RGB. Colors can shift between them, so professional print workflows convert and check color. (For black-and-white interiors, supply grayscale images.)
- Placement near the reference. Put each image close to the text that mentions it, with consistent margins and captions.
- Mind the bleed. If an image runs to the edge of the page, it needs 0.125″ bleed; otherwise keep it inside the margins.
- Caption and number figures consistently, especially in non-fiction.
Images in ebook: resolution meets reflow
Ebooks flip the priorities — you still need quality, but you're balancing it against file size and the fact that the page reflows:
- Good resolution, web-optimized. High enough to look sharp on modern high-density screens, but compressed so the file isn't bloated (large ebooks can cost more in delivery fees and download slowly).
- Size to fit small screens. An image that's too wide overflows a phone; size images to display well at the smallest common screen.
- Center and set inline. Because text reflows, images sit inline in the flow rather than being precisely anchored; center them for a clean look.
- Always add alt text — a short description for screen readers and accessibility. It's easy to skip and important to include.
- RGB color is correct for ebooks (they're read on screens).
The mistake to avoid: text baked into images
A common error is putting important text — a chart's labels, a quote, a heading — inside an image. In an ebook this text can't be resized, can't be selected, and can't be read by screen readers, so it fails readers who enlarge the font or use assistive tech. Keep real text as real text; use images for pictures, not for words.
Handling charts, tables and complex graphics
- Simple tables can be built as real tables (which reflow) in an ebook.
- Complex tables and charts often work best as high-resolution images so they don't break across devices — with descriptive alt text.
- Genuinely layout-dependent graphics (large diagrams, infographics) may justify a fixed-layout ebook to keep them intact.
- In print, all of these are placed as sized, captioned figures at 300 DPI.
An image formatting checklist
- Print: 300 DPI at final size, correct color mode, placed near references, bleed handled.
- Ebook: good-resolution but web-optimized, sized for small screens, centered, RGB.
- Alt text on every ebook image.
- No important text baked into images.
- Complex charts/tables as hi-res images or fixed-layout as needed.
- Consistent captions and figure numbers throughout.