How to fix low-resolution pictures

A picture that looks sharp on your screen can print soft or blocky. Printers want 300 DPI at the size the picture prints, and some apps quietly lower it when you save.

Quick answer

A picture needs 300 pixels for every inch it prints. Multiply the printed width and height in inches by 300 to get the pixels you need. If the picture is smaller, use a bigger original, print it smaller, or turn off image compression before exporting.

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Pixels you need (at 300 DPI)

What	Printed size	Pixels needed
Front cover, 5" x 8" book, with bleed	5.125" x 8.25"	1538 x 2475
Front cover, 5.5" x 8.5" book, with bleed	5.625" x 8.75"	1688 x 2625
Front cover, 6" x 9" book, with bleed	6.125" x 9.25"	1838 x 2775
Full-page picture, 8.5" x 11" book, with bleed	8.625" x 11.25"	2588 x 3375
Half-page picture in a 6" x 9" book	4.5" x 3"	1350 x 900
Author photo on the back	1.5" x 2"	450 x 600

Not sure what yours is? SparkPrep's free image DPI checker reads the picture in your browser (nothing is uploaded) and tells you the biggest size it prints sharp.

Stop Word from shrinking your pictures

File → Options → Advanced → Image Size and Quality.
Tick Do not compress images in file and set Default resolution to High fidelity.
Delete the pictures and insert the originals again (pictures already compressed stay compressed).
Save as PDF with "Standard (publishing online and printing)".

Canva

Always download PDF Print, never PDF Standard.
Upload the biggest version of your photo you have. Don't stretch a small picture to fill a full page.

InDesign

Window → Links shows each picture's Effective PPI. Aim for 300 or more.
On export, under Compression, don't downsample below 300.

What doesn't work

Changing the DPI number in Photoshop without adding pixels. It just relabels the file.
Screenshots. A screenshot is screen resolution (about 72 to 150).
Pictures saved from social media or messages. They're shrunk on upload. Ask for the original file.

If the original is all you have, careful upscaling can help a little. SparkPrep uses its own non-AI upscale method that keeps your art as it is (it doesn't invent new detail), and tells you honestly when a new file would be better.

Want every click spelled out? Read the full walkthrough: "Image resolution is below 300 DPI" on sparkprep.legenddary.com.

Find out what's wrong with your files before the printer does

SparkPrep checks your cover and every interior page against the exact rules Amazon KDP, IngramSpark, Barnes & Noble Press and Lulu use, tells you each problem in plain English, and can fix it for you.

Scan my book free See how SparkPrep works

The scan is free and shows how many problems your files have. To see every problem and where it is, the audit is $1.99 ($3.99 after January 1). The Advanced Audit checks every page, up to 300, for $9.99.

Questions people ask

What DPI do I need for a printed book?

300 DPI at the printed size. Line art and text-only images look best at 600.

Can I print a 72 DPI picture?

Only very small. A picture at 72 DPI prints sharp at about a quarter of its screen size.

More on this site

Fix your book's print filesPlain-English fixes for the book file problems printers reject: bleed, margins, fonts, transparency, low-resolution pictures, color, ink, page size and spine.How to add bleedHow to add 0.125 inch bleed to a book cover or interior in Canva, InDesign, Affinity or Word, how to check it, and why bleed errors come back.How to fix book marginsFix interior margin errors: KDP's inside gutter by page count, IngramSpark's 0.5 inch safety area, and margin settings in Word, InDesign and Affinity.Fix PDF page sizeIf your interior PDF is letter size but your book is 6x9, the printer shrinks or crops it. How to set the right trim size in Word and InDesign.How to embed fontsFix 'font not embedded' and font license errors in your book PDF: how to embed every font in Word, InDesign, Affinity and Canva, and how to check in Acrobat.How to flatten transparencyShadows and see-through shapes can print as boxes. How to flatten transparency and layers for KDP and IngramSpark in Canva, InDesign, Affinity and Acrobat.Fix color and ink coverageFix 'ink coverage exceeds 240%' and 'RGB found' errors: convert book files to CMYK or true grayscale and lower total ink in Acrobat, InDesign and Canva.Fix spine width and spine textFix a wrong spine width or spine text error: how to re-fit your cover for a new page count or paper, center spine text and know when spine text is allowed.

Free help from SparkPrep

Book Preflight, ExplainedWhat book preflight is, who needs it and what gets checked before KDP or IngramSpark prints your book.Print Cover SizesFull cover size charts, spine widths, barcode space and hardcover rules for KDP and IngramSpark.Rejection Messages DecodedWhat KDP and IngramSpark rejection messages really mean, in plain English, and what to do next.First Book GuideYour first print book, step by step: costs, timeline, words to know and the mistakes to skip.Free book toolsCover calculator, spine width, margins, DPI checker and page count, on sparkprep.legenddary.com.

Last updated 2026-11-01. Written by Joshua Davis, founder of SparkPrep. Numbers come from each printer's own published guides; always double-check your printer's current rules before you upload.