Peer review, acceptance & rejection guides › Figure Legends and Captions
What a complete figure legend contains
| Element | What to include | Example |
|---|---|---|
| Title | One sentence stating the main finding or what is shown | “Model accuracy rises with training data size.” |
| Method summary | How the data was obtained, briefly | “Five-fold cross-validation on the CIC-IDS2017 dataset.” |
| Symbols and colours | What each line, marker or colour means | “Blue: proposed model; grey: baseline.” |
| Error bars | Whether they show SD, SE or 95% CI | “Error bars show 95% confidence intervals.” |
| Sample size and test | n for each group and the statistical test | “n = 30 per group; two-tailed t-test, *p < 0.05.” |
| Units and scale | Units of each axis; scale bars for images | “Scale bar: 50 µm.” |
| Panels | Describe each panel (a, b, c) separately | “(a) Training loss; (b) validation accuracy.” |
How often reviewers comment on figures: real data
Figures, tables and equations came up in 20% of the 661 reviewer comments and decisions shared anonymously on ScholarsColab (135 comments, updated 18 October 2026), more than any other topic. 22 of these were on papers that were later accepted or sent for revision: figure comments are usually fixable.
Examples of what reviewers wrote:
“All graphics and pictures should be numbered as Fig.1., Fig.2., Fig.3., ...”
“All tables should be numbered as Table 1., Table 2., Table 3., ..”
“All Mathematical Equations should be edited using MathType and numbered as (1)(2)(3)...”
“There are a number of figures where some texts inside the plots or subplots are not legible.”
Common figure problems reviewers point out
- Axis labels or units missing, or text too small to read.
- Legends that do not say what error bars show or how many samples were used.
- Figures that repeat a table, or tables that would be clearer as a figure.
- Low-resolution images (most journals ask for 300 dpi or vector formats).
- Colours that cannot be told apart in greyscale or by colour-blind readers.
Received reviewer comments yourself? Share them anonymously to make this data more useful for everyone.
Frequently asked questions
What is a figure legend?
A figure legend, or caption, is the text below a figure that explains what it shows, how the data was obtained and what its symbols, colours and error bars mean, so the figure can be understood on its own.
How long should a figure legend be?
Usually one short title sentence plus a few sentences of detail. Many journals set a word limit, often around 100 to 300 words per legend.
Where does the figure legend go?
In most journals the legend goes below the figure. Tables are different: their title goes above the table.
What resolution do journals require for figures?
Most journals ask for at least 300 dpi for photos and images and 600 to 1,000 dpi for line art, or vector formats such as EPS or PDF.