Here is something most authors underestimate: a reviewer's first impression of your paper is visual. Before anyone reads your methods, they scan your figures and tables. If those are cluttered, blurry, or duplicate each other, the paper feels weaker before a single argument has been judged. Getting your display items right is some of the highest-return work you can do on a manuscript.
Figure or table? Choose deliberately
The two are not interchangeable. A figure is for a pattern — a trend over time, a difference between groups, a relationship between variables that the eye can grasp instantly. A table is for precise values a reader may want to look up or compare exactly. The cardinal sin is presenting the same numbers as both a figure and a table; pick the one that serves the reader and delete the other.
Resolution and file formats
Low-resolution images are one of the most common production problems. Prepare each figure at the size it will be printed, and at these minimums:
| Figure type | Minimum resolution | Preferred format |
|---|---|---|
| Photographs / micrographs | 300 dpi | TIFF or high-quality JPEG |
| Graphs, charts, line art | 600 dpi | Vector (EPS/PDF/SVG) or high-res PNG |
| Fine line drawings | 1200 dpi | Vector |
Wherever possible, submit graphs as vector files. Vectors stay razor-sharp at any size, so a chart exported as EPS or PDF will never pixelate the way a screenshot does. Enlarging a low-resolution image never adds detail — it only makes the blur bigger.
Designing a figure people can read
- One message per figure. If a figure is trying to say three things, it will say none of them clearly. Split it into panels (a, b, c) with a shared caption.
- Label directly. Put labels on the data where you can, rather than forcing readers to decode a legend.
- Mind colour. Do not rely on colour alone to distinguish groups — use shapes or patterns too, so the figure survives colour-blind readers and greyscale printing.
- Set type large enough. Axis text that is legible on your monitor is often too small once the figure is reduced to a single column.
Tables done right
A good table is easy to read down a column. Keep decimal places consistent, align numbers on the decimal point, give every column a clear header with units, and define abbreviations in a footnote. If a cell has no data, say why (a dash for "not applicable" is not the same as a blank for "missing"). Resist the temptation to pack twenty columns into one table — a table that needs a magnifying glass has failed.
Captions, alt text and permissions
Every figure and table needs a caption that stands alone: a reader who sees only the figure should understand what it shows, including what any abbreviations and error bars mean. Add a short alt-text description too — it makes your work accessible to screen-reader users and helps search engines index it. Finally, if you are reusing a figure from elsewhere, sort out the rights before submission: an open-licence figure needs attribution, but an all-rights-reserved figure needs written permission from the copyright holder.
A pre-submission checklist
- Every figure and table is cited in the text, in order.
- No figure and table present the same data.
- Resolution meets the journal's minimum at print size; graphs are vector where possible.
- Each caption stands alone and defines its abbreviations.
- Colour is not the only way groups are distinguished.
- Reuse permissions or attributions are in place.
Run that list before you submit and your paper will not just read better — it will look like the work of someone who takes their evidence seriously.