lancet-figure-guide · v1.0 · 2026-04-01 · sha256 c4cb92c67df24f11
lancet-figure-guide v1.0A
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---
name: lancet-figure-guide
description: "Figure and image preparation guide for The Lancet. Covers resolution (300+ DPI at 120% size), file formats (PowerPoint, Word, SVG preferred), column widths (75/154 mm), Times New Roman font, and Lancet in-house redraw policy."
license: CC-BY-4.0
compatibility: Python 3.10+, Pillow, Matplotlib
metadata:
authors: HITS
version: "1.0"
---
# The Lancet Figure Preparation Guide
## Overview
This guide provides the complete specifications for preparing figures for submission to **The Lancet** and Lancet family journals. A key distinguishing feature of The Lancet is that **most figures are redrawn by in-house illustrators** into Lancet house style. Therefore, editable source formats (PowerPoint, Word, SVG) are strongly preferred over rasterized images.
**Official reference**: https://www.thelancet.com/submission-guidelines
---
## Resolution Requirements
| Requirement | Specification |
|---|---|
| All photographic images | **300 DPI minimum** |
| Submission size | **120%** of intended publication size |
**TIP**: Supply images 20% larger than publication size to ensure quality is maintained after any resizing by the production team.
```python
from PIL import Image
def check_lancet_resolution(image_path):
"""Check if image meets Lancet resolution requirements."""
img = Image.open(image_path)
dpi = img.info.get('dpi', (72, 72))
print(f"DPI: {dpi[0]} x {dpi[1]}")
print(f"Minimum required: 300 DPI")
print(f"TIP: Submit at 120% of publication size")
if dpi[0] >= 300:
print("PASS: Resolution meets Lancet requirements")
else:
print("FAIL: Need at least 300 DPI")
return dpi[0] >= 300
```
---
## File Format
### Preferred Formats (Editable)
| Format | Notes |
|---|---|
| **PowerPoint (.pptx)** | Most preferred — easy for in-house redraw |
| **Word (.docx)** | Accepted for simple figures |
| **SVG** | Scalable vector graphics |
### Also Accepted
| Format | Notes |
|---|---|
| TIFF | For photographic images |
| JPEG | Acceptable quality |
| EPS | Vector format |
| PDF | General purpose |
### Why Editable Formats?
The Lancet's in-house illustration team **redraws most submitted figures** into the Lancet house style. Providing editable source files (especially PowerPoint) makes this process smoother and more accurate.
---
## Figure Size and Dimensions
| Layout | Width |
|---|---|
| 1 column | **75 mm** (2.95 in) |
| 2 columns | **154 mm** (6.06 in) |
| Minimum width | **107 mm** (4.21 in) |
- All panels must fit on a **single page**
```python
import matplotlib.pyplot as plt
LANCET_WIDTHS = {
'single': 75 / 25.4, # 2.95 inches
'minimum': 107 / 25.4, # 4.21 inches
'double': 154 / 25.4, # 6.06 inches
}
def create_lancet_figure(layout='single', aspect_ratio=0.75):
"""Create a Matplotlib figure sized for The Lancet."""
width = LANCET_WIDTHS[layout]
height = width * aspect_ratio
fig, ax = plt.subplots(figsize=(width, height))
fig.set_dpi(300)
return fig, ax
```
---
## Color Mode
| Purpose | Color Mode |
|---|---|
| Online publication | **RGB** |
| Print publication | **CMYK** |
- Color and black-and-white photographs both accepted
---
## Font Requirements
| Element | Font | Size | Style |
|---|---|---|---|
| Main figure heading | Times New Roman | **10 pt** | **Bold** |
| Figure legend | Times New Roman | 10 pt | Regular, single-spaced |
### Key Difference from Other Journals
- The Lancet uses **Times New Roman** (serif font), unlike most other biomedical journals that prefer sans-serif fonts
```python
import matplotlib.pyplot as plt
def set_lancet_fonts():
"""Configure Matplotlib for Lancet figure fonts."""
plt.rcParams.update({
'font.family': 'serif',
'font.serif': ['Times New Roman', 'Times'],
'font.size': 10,
'axes.labelsize': 10,
'axes.titlesize': 10,
'axes.titleweight': 'bold',
'xtick.labelsize': 8,
'ytick.labelsize': 8,
'legend.fontsize': 8,
})
```
---
## Labeling Conventions
### Rules
- **No box outlines** around graphs
- **No titles** inside graphs or artwork — include in caption instead
- Number figures in order of citation in text
### Best Practices
- Keep figures as simple and clear as possible
- The Lancet illustrators will redraw most figures, so focus on conveying data accurately rather than visual polish
---
## Image Integrity and Manipulation Policy
- Follow standard biomedical publishing ethics
- All image adjustments should be applied uniformly
- Describe any image processing in Methods
- Maintain original data for potential review
---
## Python Quick Start: Full Validation
```python
from PIL import Image
import os
def validate_lancet_figure(image_path, layout='single'):
"""Full validation of a figure against Lancet requirements."""
img = Image.open(image_path)
issues = []
# 1. Resolution check (300 DPI at 120% size)
dpi = img.info.get('dpi', (72, 72))
if dpi[0] < 300:
issues.append(f"Resolution {dpi[0]} DPI below 300 DPI minimum")
# 2. Dimension check
widths_mm = {'single': 75, 'minimum': 107, 'double': 154}
if layout in widths_mm and dpi[0] > 0:
actual_w_mm = (img.size[0] / dpi[0]) * 25.4
target = widths_mm[layout]
# Should be 120% of publication size
target_120 = target * 1.2
print(f"Width: {actual_w_mm:.1f} mm (target at 120%: {target_120:.1f} mm)")
# 3. Format recommendation
fmt = img.format
if fmt and fmt.upper() in ('TIFF', 'JPEG', 'PNG'):
print(f"NOTE: Format is {fmt}. Lancet prefers PowerPoint/Word/SVG for redrawing")
# Report
print(f"=== Lancet Figure Validation ===")
print(f"Dimensions: {img.size[0]} x {img.size[1]} px")
print(f"DPI: {dpi[0]} x {dpi[1]}")
print(f"Color mode: {img.mode}")
if issues:
print(f"\nISSUES FOUND ({len(issues)}):")
for issue in issues:
print(f" - {issue}")
else:
print("\nAll checks PASSED")
return len(issues) == 0
```
---
## Pre-Submission Checklist
Before submitting figures to The Lancet, verify:
- [ ] Photographic images at 300+ DPI
- [ ] Images supplied at **120% of publication size**
- [ ] Preferred format: PowerPoint, Word, or SVG (for in-house redraw)
- [ ] TIFF/JPEG/EPS acceptable for photographs
- [ ] 1-column figures: 75 mm wide
- [ ] 2-column figures: 154 mm wide
- [ ] All panels fit on a single page
- [ ] Font is Times New Roman (10 pt bold for headings)
- [ ] No box outlines around graphs
- [ ] No titles inside graphs (use captions)
- [ ] Figures numbered in order of text citation
- [ ] Data clearly and accurately represented (Lancet will redraw)
- [ ] Original data retained for review
---
## References
- Lancet Submission Guidelines: https://www.thelancet.com/submission-guidelines
- Lancet Artwork Guidelines: https://www.thelancet.com/pb/assets/raw/Lancet/test/artwork-guidelines-aug2015.pdf