Resolution is the most misunderstood technical requirement for scientific figures. Most researchers know "300 DPI" as a rule of thumb — but it applies only to some figure types, and many journals require 600–1200 DPI for line art. Getting this wrong is one of the most common reasons figures are rejected in production.
What DPI means and why it matters for print
DPI stands for dots per inch — the number of pixels printed per linear inch. At low DPI, figures look pixelated or blurry in print. At high DPI, they are crisp.
The key insight: DPI is meaningful only at a specific physical size. A 3000-pixel-wide image has a different DPI depending on whether you print it at 3 inches (1000 DPI) or 10 inches (300 DPI).
Most researchers set DPI incorrectly because they:
- Export at screen size (72–96 DPI) and assume "high resolution" refers to pixel count alone
- Resize a low-DPI image to hit a DPI number (which upscales and blurs it)
- Apply a single DPI value to all figure types
The correct DPI by figure content type
| Figure type | Minimum DPI | Notes |
|---|---|---|
| Photographs, gel images | 300 DPI | At final print width |
| Micrographs, fluorescence images | 300 DPI | At print size |
| Combination figures (image + line art) | 500–600 DPI | Match to the line art requirement |
| Statistical graphs, bar charts, box plots | 600–1200 DPI | Line art standard |
| Diagrams, flow charts, schematics | 600–1200 DPI | Vector if possible |
| Text-only panels | 600–1200 DPI | Aliasing on letterforms at lower DPI |
Journal-specific DPI requirements
| Journal | Photographs | Line art | Combination |
|---|---|---|---|
| Nature | 300 DPI | 1000 DPI | 500 DPI |
| Cell Press | 300 DPI | 1000 DPI | 500 DPI |
| Science | 300 DPI | 1000 DPI | 600 DPI |
| PNAS | 300 DPI | 600 DPI | 600 DPI |
| EMBO Journal | 300 DPI | 800 DPI | 600 DPI |
| PLOS ONE | 300 DPI | 600 DPI | 600 DPI |
| eLife | 300 DPI | 600 DPI | 600 DPI |
See our dedicated guides for Nature figure requirements and Cell Press figure guidelines.
How to calculate the right pixel dimensions
Formula:
Pixel width = (physical width in inches) × DPI
Examples:
For a single-column Nature graph (89 mm = 3.5 in) at 1000 DPI (line art):
3.5 × 1000 = 3500 pixels wide minimum
For a full-width Nature photograph (183 mm = 7.2 in) at 300 DPI:
7.2 × 300 = 2160 pixels wide minimum
For a single-column Cell graph (85 mm = 3.35 in) at 1000 DPI:
3.35 × 1000 = 3350 pixels wide minimum
The upscaling trap
If your figure is 800 px wide and you need 3500 px, do not upscale it. Upscaling blurs the image and adds fake pixels — it does not add real detail.
The only solutions are:
- Recreate the figure at the correct size (best)
- Export from a vector source (graphs from R, Python, Illustrator, FigureGuild) — vector exports are resolution-independent; you specify DPI at export time without losing quality
Vector vs raster for resolution control
Vector figures (from R/ggplot2, Python/matplotlib, Illustrator, Inkscape, FigureGuild) are resolution-independent. When you export a PDF or EPS, it has no inherent DPI — it renders at whatever DPI you specify at print time. When you rasterize to TIFF/PNG, you choose the DPI freely.
This means: if your graph is made in a vector tool, DPI is set at export, not at creation. You can always export at 1200 DPI from a vector source without quality loss.
Raster figures (photographs, microscopy, gel scans) have a fixed resolution from the moment of capture. You cannot increase it by upscaling.
How FigureGuild handles resolution
FigureGuild builds all charts as vectors internally. When you export, you choose your DPI: 300, 600, or 1200. The graph renders at the exact pixel dimensions needed for the physical size and DPI you specify — no upscaling, no blurring.
Build your figure at the right resolution →
Checking your current figure DPI
In most image editors: Image → Image Size → uncheck "Resample" → change the width to your target print size in inches → read the DPI that results.
In macOS Preview: Tools → Show Inspector → Image tab → shows PPI (same as DPI for screen viewing)
In Adobe Acrobat (for PDFs): Output Preview → check pixel dimensions and infer DPI from document size
In ImageJ (for microscopy): Image → Properties → shows pixel size; calculate DPI from print size
FAQ
Is 300 DPI always enough for scientific figures? No. 300 DPI is the minimum for photographs. For graphs, diagrams, and line art, most journals require 600–1200 DPI. Always check your specific journal's requirements for each figure type.
Why do journals require different DPI for photographs vs line art? Fine lines and text in line art alias (create jagged edges) at 300 DPI. Photographs, which have smooth tonal gradations, look fine at 300 DPI because there are no sharp transitions to reveal pixelation.
My figure looks sharp on screen but blurry in print — why? Screens display at 72–144 PPI. Print requires 300–1200 DPI. A figure that looks sharp on screen may be only 72 DPI, which is 4× too low for print. Always check your DPI at the physical print dimensions, not screen pixel dimensions.
Can I submit vector files instead of specifying DPI? Yes, for line art. EPS and PDF (vector) files are resolution-independent and preferred by most journals for graphs and diagrams. Production renders them at whatever DPI they need.
How do I export at 1200 DPI from Python/matplotlib?
fig.savefig("figure.tiff", dpi=1200, bbox_inches="tight")
Set the figure size in inches before saving to match your target physical dimensions.