What DPI do you need for printing?
DPI (dots per inch) measures how densely an image’s pixels are packed when printed. For text and photos, 300 DPI prints sharp; 150 DPI is readable but slightly soft around the edges; above 300 DPI most people can’t see any difference. If you just want to print pictures on A4 paper, you don’t need to set any of this: the layout tool exports images at 300 DPI and keeps PDF pages as vector graphics.
DPI, PPI and pixels
- Pixels are the grid of dots that makes up an image. A phone screenshot might be 1080×2400 pixels.
- PPI / DPI describes how tightly those pixels are packed on paper. People use the two terms interchangeably; this article says DPI.
- The relationship is simple: printed width in inches = pixels ÷ DPI. One inch is 25.4 mm.
So an image doesn’t really “have” a DPI on its own. What matters is how big you print it. The same 1080-pixel-wide screenshot is about 300 DPI when printed 90 mm wide, but only about 150 DPI at 180 mm wide.
How much DPI do you need?
| Content | Recommended |
|---|---|
| Text, receipts, ID cards | 300 DPI |
| Photos | 200–300 DPI |
| Drafts, rough copies | 150 DPI |
Your A4 paper measures 210×297mm. To work out how many pixels fill it, use mm ÷ 25.4 × DPI, or simply inches × DPI.
Why screenshots print less sharply than they look on screen
A screenshot has exactly as many pixels as your screen. Stretch it larger than those pixels can support and the DPI drops, giving text jagged edges. A typical 1080-pixel-wide phone screenshot still has about 300 DPI at around 90 mm wide. A small window captured on a computer has far fewer pixels, so blowing it up makes it fuzzy.
The fix is not to print small screenshots too large. On a computer you can drag a corner to make a picture smaller; the layout tool keeps its proportions.
Printer DPI is a different thing
When a printer advertises 1200 or 4800 DPI, that’s about how finely it can place ink or toner dots, not the image resolution. Any of them will print a 300 DPI image cleanly.
PDFs aren’t limited by DPI
Invoices and other documents saved as PDF are usually vector files: text is described by outlines rather than pixels, so it stays sharp at any size. When you export a PDF, uncropped PDF pages are embedded as vectors, unchanged; only images (and cropped PDF pages) are embedded at 300 DPI.
Want to try printing a few pictures? Open the multiple photos on one page tool.