How to build a multi-panel figure with A, B, C labels

Most papers need one. Most are assembled by pasting images into PowerPoint or Illustrator, which is where the inconsistencies creep in.

Label conventions

Capital letters, bold, top-left of each panel, outside the plot area rather than inside it. Most journals use A, B, C. Some use lowercase. Check yours.

Reference them in the caption and text as "Figure 2A", not "the left panel".

Consistency is what reviewers notice

Every panel should share:

• The same font and font size
• The same axis line weight and tick length
• The same colour palette, with a given condition the same colour throughout
• The same error bar convention, stated once in the caption

Mismatched panels are the most common cosmetic reason a figure comes back.

Layout

Order panels by the logic of your argument, not by when you made them. Reading order is left-to-right, top-to-bottom.

One shared legend rather than a legend per panel, where the panels use the same conditions. Align axes across panels that share a scale so the reader can compare directly.

Build at final width

Assemble at the journal's actual column width, typically about 90 mm single or 180 mm double, so that text sizes are correct at print size rather than after scaling. See journal figure width.

Export as vector

PDF or SVG for line art, so panels stay crisp at any size. See exporting figures for journal submission.

In Plotara

The Figure Builder handles multi-panel layout at 90 mm and 180 mm with automatic, editable A/B/C labels, and every panel inherits the same style settings.