Here is what the publishers actually write down, and the one habit that avoids most of the trouble.

Start from the column width

The first number to fix is the width the figure will be printed at. Type size, line weight and resolution are all stated at final size, so they only mean something once you know what final size is.

The failure looks like this: you draw at whatever width your software opened with, and the journal scales it down at layout. Reduction shrinks the lettering and the strokes along with the artwork. A chart drawn at 190 mm and reduced to 90 mm takes 7 pt axis labels down to 3.3 pt, which is below every stated minimum.

What 300 dpi really means

Resolution is only defined at a physical size. Elsevier states it as an equation: pixels equal dpi multiplied by print size in inches.

A 90 mm figure at 300 dpi is 1063 pixels wide. The same 1063-pixel file placed at 190 mm is a 142 dpi figure, and no setting in any application changes that.

The targets differ because they describe different content:

• Elsevier: 300 dpi for halftones, 500 dpi for combination art, 1000 dpi for line art
• PLOS: 300 to 600 dpi, with files capped at 10 MB
• Nature: at least 300 dpi at the maximum size the image will be used

Line art gets the highest number because a hard black edge on white is where sampling artefacts show most.

Raising the dpi afterwards does nothing

Nature warns about this directly, and it is one of the most common mistakes. Increasing an image's resolution in an artwork program does not add detail. If the file was too small, go back to the source and export it again at the right size.

The check that takes a minute

Nature's advice predates modern software, and it still works. Look at the figure at the smallest size it might be printed, and confirm the lettering is readable and the lines are heavy enough.

The modern version is to place the artwork in a document at exactly 89 or 90 mm, print it on paper, and look at it. Screens flatter figures. Paper does not.

Where the publishers disagree, follow the document for your target journal. We keep the wider version, including vector versus raster, type sizes and colour, in our guide on how to make scientific figures.

From the team behind Scientific Figure, an AI figure generator for researchers. Publisher rules change, so check the journal's own page before you submit. Drafted with AI assistance and checked against our sourced guide.