Understanding how to format images in a book saves authors from the two most common visual problems in self-publishing: pictures that look sharp on a screen but print soft and grey, and ebook files so heavy that they load slowly and cost more to deliver. This guide covers resolution, sizing, placement, captions, colour, bleed, and file size, so your images look deliberate on Kindle and in print.
Resolution and File Types That Actually Work
Print and screen judge images by different rules, and resolution is where most mistakes begin. For print, prepare images at 300 DPI at the exact size they will appear on the page. DPI means dots per inch, so a photograph printed four inches wide needs about 1,200 pixels across to reach 300 DPI. A picture that looks fine on your laptop at a small size may only hold a quarter of the pixels print needs.
Never solve a low resolution file by simply enlarging it in your layout software. Stretching spreads the same pixels over a bigger area and lowers the effective resolution further, which is why the printed result looks soft or blocky. If an image is too small, print it smaller, find the original file from the camera or illustrator, or replace it. There is no setting that invents detail that was never captured.
Line art is the exception that needs even more care. Diagrams, signatures, maps, and black and white drawings with hard edges can look rough at settings that suit photographs. Prepare clean line art at a higher resolution where your tools allow it, keep lines pure black, and avoid grey anti aliased edges that print as fuzz.
For file types, use high quality JPEG or TIFF files for print photographs, and PNG for graphics that need crisp edges or transparency. For Kindle, JPEG is the workhorse for photographs, while PNG or GIF style graphics suit simple diagrams. Whatever the format, keep an untouched master copy of every image outside your book file, so you can prepare a print version and an ebook version from the same clean source.
How to Format Images in a Book for Print
In a print book, every image has a fixed home. You choose its width, its position on the page, and the space around it, and every printed copy repeats that choice exactly. Set images at a consistent width where you can: full text width for important photographs, half width for smaller supporting pictures. Consistency reads as professionalism, while random sizes on every page look accidental.
Anchor each image close to the paragraph that refers to it. Readers should not have to hunt several pages forward or back to find the photograph a passage describes. If page layout forces a move, adjust the reference in the text, for example by naming the figure number instead of saying the photo below.
Mind the gutter. The inner margin of a bound book curves into the spine, so keep faces, text inside diagrams, and other vital detail well away from the centre fold. Our step by step guide to how to format a paperback interior for KDP covers the margin and gutter numbers that keep both text and images safe on the printed page.
Check images in the final print PDF at full size, not in your editing software. Zoom to 100 percent and look for softness, jagged edges, and text inside images that has become too small to read. Then order a proof copy. Paper reveals problems screens hide, especially pale images that print even paler and dark images that fill in to near black.
Formatting Images for Kindle and Other Ebooks
Ebook images live in a flowing river of text. The reader can change font size, rotate the device, or read on a phone, and your image must survive all of it. The core rule is to let the image size itself relative to the screen instead of fixing it to one device. An image set to a sensible percentage of screen width, or capped at the full width, adapts gracefully from a small phone to a large tablet.
Place images inline, between paragraphs, rather than floating them with text wrapped around the side. Text wrapping that looks elegant in a print layout often breaks in an ebook, leaving gaps, overlaps, or pictures stranded far from their captions. Inline placement is plainer, but it is predictable on every device, and predictable wins.
File size is the hidden ebook issue. Every image adds weight, and a heavy book downloads slowly and can carry higher delivery costs on some platforms, which come out of your royalty. Prepare a separate ebook copy of each image: sized for screens rather than print, compressed with care, and checked so compression has not turned faces blotchy or text unreadable. Books with a handful of photographs rarely struggle, but illustrated books, cookbooks, and travel books can grow very heavy without this step.
Test on more than one screen before you publish. Preview the book on a phone sized view and a tablet sized view, in light and dark reading modes if your previewer offers them. Images with white backgrounds can glare in dark mode, and transparent graphics can vanish against a dark screen, so a quick check tells you whether a simple white border or a filled background is needed.
Sizing, Placement, Captions and Alt Text
A caption does three jobs: it confirms what the reader is looking at, it credits the source when one is needed, and it carries information for readers who cannot see the image clearly. Keep captions in one consistent style throughout the book, set smaller than body text, and placed directly under the image they describe. Number captions in nonfiction, as in Figure 3 or Photo 3, whenever the text refers back to images later.
Alt text is a short written description of an image that screen readers speak aloud for blind and low vision readers. Add it to ebook images during formatting, and keep it factual and brief: describe what matters in the picture, and skip phrases such as image of. Purely decorative images, such as a small ornament between scenes, need no description and can be marked as decorative where your tool allows.
Children and illustrated books raise the stakes on all of this, because the pictures are the product. If you are making one, our guide to how to self-publish a children's picture book walks through the full process, and its image requirements show why planning art size and placement before illustration begins saves expensive redraws later.
Whatever your genre, build a simple image list as you format: file name, page or chapter, final size, caption, and credit. This list catches missing credits, duplicated files, and the classic error of placing a low resolution draft image instead of the finished version. It also makes later corrections and new editions far easier.
Colour, Greyscale and Bleed for Full Page Art
Decide early whether your print edition is colour or black and white inside, because that single choice shapes cost, pricing, and image preparation. Colour printing costs more per copy, so many text led books print interior images in greyscale. Convert colour photographs to greyscale yourself rather than letting the printer do it, and then adjust brightness and contrast: reds and greens that look distinct in colour can merge into the same grey, and a conversion you control protects the detail that matters.
For colour print work, prepare images in the colour mode your printer asks for, and expect some shift between screen and paper. Screens glow and paper does not, so printed colour usually looks a little darker and less vivid. A proof copy is the only honest preview, and small brightness adjustments after a first proof are normal even for experienced publishers.
Bleed applies when an image runs to the very edge of the page. In that case the artwork must extend 0.125 inches beyond the trim line on every bleeding side, so that tiny cutting variations never leave a white sliver at the edge. Full page illustrations, picture book spreads, and full bleed photographs all need this extension built into the source file from the start. You cannot add convincing bleed later by stretching a finished image, because the stretched edges smear.
Keep important content out of the bleed and edge zones. Faces, page numbers, and text inside an image should sit safely inside the page, with the bleed area holding only background that can afford to be trimmed. Treat the outer edge and the spine edge with equal care, and picture book spreads need the centre checked too, so a character does not disappear into the binding.
How Folio Authors Handles Your Book Images
Image problems are easier to prevent than to repair after a rejection or a disappointing proof. Folio Authors brings assessment, editing, formatting, cover design, and publishing together in one dashboard, so the same team view carries your illustrations from the manuscript you upload to the Kindle file and the print interior, with one consistent set of files for each edition.
If you want a second pair of eyes before you commit, your first assessment is free, and it includes a 500 word editing sample, with no card needed. Folio also offers custom formatting at $100 if you would rather a person prepared your image led interior for you. Publishing starts with Amazon KDP at $99 one time, the Standard plan is $150 one time and unlocks all Folio tools, and you keep 100 percent of your rights and royalties throughout.
Frequently Asked Questions
What resolution should images in a book be?
For print, 300 DPI at the size the image will appear on the page is the standard to aim for, with clean line art often prepared higher. For ebooks, screens need fewer pixels, but you should still start from the best quality master file and prepare a compressed screen copy rather than using a small, poor quality original.
Why do my images look blurry in print?
Usually because the file did not hold enough pixels for its printed size, or because it was enlarged during layout, which lowers its effective resolution. Check each image at its true print size, replace small files with originals where you can, and view the final print PDF at 100 percent before ordering a proof.
How big can my Kindle book file be?
Platforms allow large files, but heavy books download slowly and can attract higher delivery costs that reduce your royalty. The practical answer is to keep the file as lean as good quality allows: compress ebook copies of images, remove unused files, and reserve full print resolution images for the print edition.
Should I print interior images in colour or greyscale?
Choose based on the book and the maths. Colour suits picture books, cookbooks, and travel books where colour carries the content, but it raises print cost and therefore price. For most text led books, careful greyscale conversion you control yourself gives a clean, affordable result.
What is alt text and does my book need it?
Alt text is a short description of an image that screen readers read aloud, making your ebook accessible to blind and low vision readers. Informative images should have it, written briefly and factually. Purely decorative images can be marked decorative instead, so readers are not interrupted by descriptions that add nothing.
The Bottom Line
Good image formatting comes down to preparing the right file for each edition: 300 DPI and fixed, careful placement for print, and lighter, flexible, well described images for Kindle. Work from master files, control your own greyscale conversions, build bleed into full page art from the start, and always judge the result in a previewer and a printed proof.
Images are often the part of a book readers remember most. A little discipline with resolution, size, and captions makes sure they remember yours for the right reasons.
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