I was commissioned to map the world of An Ember in the Ashes, the New York Times bestselling debut novel by Sabaa Tahir.

It’s great to take on a map of a new world. Sabaa and Penguin had a great outline sketch—and rich notes on the world. The primary civilization is Roman-esque, alongside a desert culture, and some border nations.

I started by taking that and throwing together a quick sketch. This stage of any map is to get all the main features in the right place, and get sign off. At this point I tweaked the rivers to make more geographic sense, and layout the text.

From this point, there were some rounds of refinement on the precise locations of the main cities. Sabaa answered the questions about the terrain in the Empire, the cities, the styles, from the city of Serra to Kauf Prison.

The trick here is to get the map all but final. All the line work should show all the key features, sell the terrain, fit all the text in, and make it readable. If there was a need for a pure black and white line art map, this stage should be ready for that.

The final stage is to colour the map. Mostly, the important task here is to not obscure the details.

The colours enhance the line art—differentiating the desert from the wastes, from the farmland and the cold north. I like the deep blue oceans we ended up with here—the dark tones throw the whole map into relief.

Between the line art and the final, I added illustrations for each of the locations. The different cities have a sense of different cultures—from Roman, to Moroccan desert dwellings, to nomad tent cities. The trick for these is to get the sense of a city, without drawing every single building.

Here’s a detail of Serra and Blackcliff:

This is the full size version of the map, three times larger than anyone ever sees it. By illustrating the map at this level of detail, the shrunk down version of the map looks subtly detailed.

So there you have it. One brief, three rounds of illustration and revision, and a final world map for a burgeoning new writer, and a wonderful new world.

This article originally appeared on Jonathan Roberts’ blog, Fantastic Maps.

Sabaa Tahir’s An Ember in the Ashes is available now from Penguin Young Readers.

Jon Roberts mapped the Lands of Ice and Fire for A Song of Ice and Fire, the Milky Way for After Earth, and the city of Oxford for his own wedding. When he’s not mapping, he enjoys gaming and visualizing complex datasets. Yes, really.