| name | pnas-figures |
| description | Use to finalize PNAS display items — column-width sizing (~9 / 11.4 / 18 cm), minimum font sizes, show-the-data with n and defined error bars, scale bars, colorblind-safe palettes, legend structure, image integrity, and color-mode notes. Enforces figure rigor before submission. |
Display Items (pnas-figures)
When to trigger
- Figures and tables push the page/item allowance (
pnas-writing).
- Fonts are unreadable at print size, or colors are not colorblind-safe.
- Bar charts hide the underlying data (no points, no n).
- Panels are screenshots of software output pasted into the figure.
- You are unsure which column width to design to.
Sizing for PNAS columns
PNAS is a multi-column journal; design each figure to render at a standard print width without rescaling text:
- 1 column ≈ 9 cm wide
- 1.5 column ≈ 11.4 cm wide
- 2 columns (full width) ≈ 18 cm wide
Confirm exact widths in current PNAS author/digital-art guidelines.
- Minimum font in the final figure: ~6–8 pt (sans-serif, e.g., Helvetica/Arial), legible after reduction to print size.
- Line weights ≥ ~0.5 pt; avoid hairlines that vanish in print.
- Submit at the required resolution (line art high-dpi; halftones/photos at the specified dpi) — confirm specs.
Show the data, not just the summary
- Replace bar-of-means with dot plots / box+points / violins+points wherever n is small.
- Always state n in the legend, and what n is (cells? animals? subjects? independent experiments?).
- Error bars must be defined in the legend (SD vs SEM vs 95% CI) — never undefined.
- For images (blots, micrographs): include scale bars, and keep full, uncropped key blots for SI Appendix.
Color and accessibility
- Use a colorblind-safe palette (avoid red/green as the only contrast).
- Don't encode meaning by color alone — add shape/pattern/labels.
- Color mode: prepare figures in RGB for online; PNAS prints in color and may request or convert to CMYK for print — confirm the current color-figure policy and any charges. Check that figures remain interpretable in grayscale.
- No rainbow/jet colormaps for continuous data — use perceptually uniform maps (viridis, etc.).
Figure legend structure
Each legend: a short title sentence (the claim of the figure), then per-panel descriptions (A, B, C…), then statistics (test, n, error-bar definition, exact P or values). The legend should let the figure stand alone.
Integrity rules (non-negotiable)
- No selective deletion, splicing, or beautification of gels/blots/images without a labeled boundary; disclose any grouping.
- Quantitative comparisons must come from the same experiment/exposure.
- Keep unprocessed source images and source data — PNAS may request them (
pnas-data).
Multi-panel discipline
- Keep panels purposeful; if a figure sprawls, split it or move panels to SI Appendix.
- Consistent axis scales across comparable panels.
- One message per figure; the legend title states it.
Output format
【Item count】 figures + tables vs page/item allowance (confirm guidelines) → ok / over
【Sizing】 designed at 9 / 11.4 / 18 cm? fonts ≥ ~6–8 pt? yes/no
【Data shown】 points + n + defined error bars? yes/no
【Color】 colorblind-safe? RGB online / CMYK-print aware? grayscale-readable? yes/no
【Integrity】 scale bars / uncropped blots in SI / source data kept? yes/no
【Fixes】 [...]
【Next】 pnas-statistics
Anti-patterns
- Do not paste raw Stata/Prism/ImageJ screenshots as figures.
- Do not use bars to hide n=3 with huge spread — show the points.
- Do not leave error bars undefined or mix SD and SEM across panels.
- Do not rely on red-vs-green as the sole encoding.
- Do not assume color print is free — confirm the color policy.
