Cartography & map design
The decisions that turn a correct plot into a map someone can read: hierarchy, colour, labels and export.
This topic is about the gap between a correct plot and a map somebody can read. The data can be right and the map still fail, because a map is an argument and the reader has to be able to follow it.
Most of it comes down to hierarchy. Visual weight should follow importance, and on almost every map the largest thing — the background, the coastline, the study-area boundary — is the least important thing on it. After that: a classification scheme is a claim about the distribution, a colour ramp for sequential data says something different from one for diverging data, labels have to be resolved after the figure is drawn because they live in screen space, and a scale bar asserts something that is only true in a projected CRS.
Below: the concepts cover hierarchy, colour and the decisions a map encodes; the how-to guides build legends, labels and export-ready figures; and the fixes are the maps that come out unreadable rather than wrong.
🧭 Start with the concepts
The ideas the how-to guides below assume you already have.
- Visual Hierarchy Explained: What a Map Reader Sees First
- Colour on Maps Explained: Sequential, Diverging and Qualitative
- Labelling Explained: Why Automatic Map Labels Collide
- Which Map Elements Are Actually Required
- Map Scale Explained: How Much Detail a Scale Can Hold
- Accessible Maps Explained: Contrast, Text and Alternatives
Show every concept in this topic
- Counts, Rates and Densities: What a Demographic Map Should Show
- Attribution requirements explained: OpenStreetMap, Copernicus and national data
- Hex and Tile Maps Explained: Equal Shapes for Equal Units
- Cartograms Explained: Trading Geography for Size
- Election Map Colours Explained: Diverging Scales, Midpoints and Breaks
- Animated Maps Explained: When Motion Helps and When It Misleads
- Small Multiples vs Animation: Choosing How to Show Change on a Map
- Time-Series Maps Explained: Events, Tracks, Snapshots and Fields
- Flow Maps Explained: What a Line on a Map Says About Movement
- Vector Field Maps Explained
⚙️ Then do the task
Step-by-step walkthroughs with code you can copy and adapt.
- How to Choose and Test a Colour Ramp in Python
- How to Check a Map for Colour-Blind Readers
- How to Label Map Features Without Overlaps in Matplotlib
- How to Add a Scale Bar and North Arrow to a Python Map
- How to Build a Print-Ready Map Layout in Matplotlib
- How to Export a Map at Print Quality: DPI, Vector and Fonts
Show every how-to guide in this topic
- How to Add an Inset and Locator Map in Python
- How to Make a Map Series with Consistent Symbology
- How to Build a Reusable Map Style Module
- How to draw a strip map of events along a route
- How to Make a Contiguous Cartogram in Python
- How to Make a Dorling Cartogram in Python
- How to Make a UK Election Hex Map in Python
- How to Make a Value-by-Alpha Election Map in Python
- How to Make a Non-Contiguous Cartogram in Python
- How to Make a US State Tile Grid Map in Python
- How to Make Small-Multiple Maps in Python
- How to Export a Map Animation as GIF, MP4 or WebP in Python
- How to Make a Flow Map in Python
- How to Draw a Land Cover Transition (Sankey) Diagram in Python
- How to Make a Bivariate Map of Health and Poverty in Python
- How to Draw a Wind Arrow Map in Python
- How to Plot Wind Barbs in Python
- How to Draw Wind Streamlines in Python
🔧 When it breaks
The errors this topic produces, with the cause explained rather than just the command.
- Fixing Map Labels That Overlap or Get Clipped
- Fixing Map Text That Is Too Small in the Exported File
- Fixing Missing or Substituted Fonts in an Exported Map PDF
- Fixing a Map Export That Is Hundreds of Megabytes
- Fixing Map Colours That Change Between Screen and Print
- Hex Map Comes Out Scrambled: Offset Coordinates and Negative Rows
Show every fix in this topic
- Cartogram Distorted Beyond Recognition: Twisted Shapes and Invalid Polygons
- Why Do the Colours Flicker in My Map Animation?
- Why Does My GIF Map Animation Have Colour Banding?
- Why Does My Map Animation Jump and Jitter Between Frames?
- Why Is My Map Animation File So Large, and How Do I Shrink It?
- Why Is My Flow Map an Unreadable Tangle of Lines?
- Why Are the Colours on My Land Cover Map Wrong?
Learning paths through this topic
A curated route rather than a list — the guides in the order that builds on itself.
Related topics
Subjects that keep coming up alongside this one, most overlap first.