Map Projections in the Web

Following our tutorial on creating maps in the browser–Get Started Creating D3 Maps–I thought it would be fun to explore map projections in the web with JavaScript.  D3 in particular gives us the opportunity to be very creative in how we render geospatial data with the ability to choose from and customize many different projections.

See the Pen D3 Projected Halftone Pattern by Jacob Wasilkowski (@jwasilgeo) on CodePen.

Reduce those dimensions

Locations of our geospatial data exist somewhere on our three-dimensional planet, but we have to make two-dimensional maps for our flat electronic screens (or pieces of paper!).  Deciding which map projection to use is an exercise in telling your data how it needs to bend, twist, rip, and transform from a three-dimensional reality to a two-dimensional medium.

Different map projections exist for different reasons and any choice made is a trade-off for which property you’d like to preserve from your original data, including area, shape, angle, or distance.  For example, if you need to maintain the correct areas of countries, then you may have to give up caring about their shapes becoming distorted.  (This would be called an equal-area projection, by the way.)  There is no perfect map projection to fit all situations.

Center or rotate a web map?

Most of the web maps we interact with use some variation of the Mercator projection. It is known as a conformal projection and nearly always is rotated in a way that is visually very familiar and comfortable to us: north is up, south is down, and land masses closer to the poles are distorted in area and appear much bigger than they actually are.

Moving around on this kind of web map changes the center location, which is similar to shifting a paper map around on a table.  When you navigate up to view Greenland in a web map, it would be like moving a paper map down, right?  Greenland’s area is still distorted and bloated.

But when you interact with a globe in real life you rotate it.  The same is actually possible for all map projections, and in D3 we can rotate along 3 different axes.  If the world’s landmasses look unfamiliar when rotating a map’s projection it doesn’t mean we are doing something wrong.  Perhaps unconventional, but not necessarily wrong.  Our three-dimensional data is simply being instructed how to reshape itself onto a two-dimensional map.  If we were to rotate the same example web map to Greenland its area would be much more accurate, but at the cost of other landmass areas becoming distorted.

Here’s a demo showing the differences between centering and rotating.  The top row uses the Mercator projection while the bottom uses the Orthographic projection which resembles a globe (but a flat globe in 2-D).

See the Pen D3 Map Projections: Centering vs. Rotating by Jacob Wasilkowski (@jwasilgeo) on CodePen.

Circles, circles everywhere

What if we were gods and could sculpt perfectly circular islands of the same size and then place them evenly around the planet?  I suppose even on our best days we don’t have this power–sorry–but we can at least draw them on a map.  These regularly spaced circles, called Tissot’s indicatrices, show the unique distortions of each projection by stretching, warping, and also moving the circles around.

The regions in the next demo that contain evenly distributed, small circles exhibit very little or no distortion.  But as the circles grow, morph into other shapes, or move away or closer together, then the distortions of a projection are uniquely affecting the sizes, angles, and distances between geographical features throughout the map.

See the Pen D3 Map Projections by Jacob Wasilkowski (@jwasilgeo) on CodePen.

Which one is your favorite?  Are any of these cool enough to be a tattoo?

Go make some maps

If you want to experiment with map projections, visit Get Started Creating D3 Maps and start making changes to the Canvas demo or SVG demo.

Look for the JavaScript code block starting with var projection = d3.geoMercator() and replace it with another projection documented at d3-geo, d3-geo-projection, or perhaps d3-geo-polygon.

Learn more

Have fun distorting the shape of the world!

Using a 1950s Diner Theme as Inspiration for my Donut Map

Graphic designers (and mappers who are into graphic design), this post is for you! The first thing you need to know about this map is that most of the work was not on the map at all (scroll to bottom to see full illustration). It was on the surrounding design: the donut, the counter-top, the tissue paper (did you notice that subtle grease stain?) As far as maps go, the map itself was pretty straightforward. I hesitate to call it easy, because no matter how experienced you are at graphic design, mapping software has a learning curve at first. But it wasn’t the most involved map I’ve made. Still, there were cartographic choices that I had to make for a contiguous/mainland USA map with 31 points and chunky labels. I’ll share some of those things below. If you’d like to learn about how to add a map to your design, I posted that method that I used here.

This post is a sort of celebration of incorporating maps into your design, by sharing some of those techniques.

Donut Map by Sarah Bell

1956 Diner theme

Tabletop design

Pattern and Hue

I went with a 1950s-60s diner theme for this design project, so clearly I had to make a mid-century table top. We’ve all seen the type of countertops and tables to which I refer. I decided to make an original design of what I might see in a dream about 1950s diners. So I used an alternating 4-point star repeating pattern with a blue and green that are so similar that – to know they differ – you’d have to see them adjacent to one another. It seems like the truly period tables like this don’t have quite as bold of colors as the current versions being made today. The reason for this could be that all the originals I’ve seen have faded a little bit. Regardless, I wanted to have that original look, so these two similar-but-different colors help give that look that either the pigment wasn’t very bold, or some sunlight has helped the blue and green hues become more similar over time. The tabletop’s repeating pattern is the first of the two layers for the table, and sits at the bottom of the entire design in Illustrator.



A lot of the old 1950s formica countertops with smooth texture still have a textured appearance as part of their design. To accomplish this, I created a layer just above the pattern layer. Inside of this upper layer, I added a rectangle with a really pale yellow-to-green-to-pink gradient. Then I added a transparency mask to this rectangle from a photo of marble; I also greatly increased the contrast of this photo prior to using it as a mask. Then, I just inverted the mask, which made this upper tabletop layer sort of visually incorporate itself with the bottom pattern layer.

I tilted the pattern a little, to make it look like the donut-paper-bakery tissue setup was a little more organically placed.


Bakery Tissue

Base layer

The bakery tissue is made of 5 layers! To do any sort of rendering in Illustrator, all that drawing I’ve done over the years has been key for me personally. Just like in the graphite arts, I add the shading last in Illustrator. So the bottom most layer was made last for this bakery tissue. I’ll start with what’s – let’s say – the base of this bakery tissue. It’s a paper-bag-brown color to look like the brown bakery tissue. I then gave each of the left and right sides pinked edges. Then I just worked the edges a little to make it look more like a realistic once-folded tissue.


To get the lighting of this bakery tissue, I imagined a diner full of bright lights and windows letting in some natural sunlight. Still, there was a brightest light source that I imagined towards the upper left of this table. So I copied the base layer, and used a linear gradient to put some bright lines where I could imagine the light hitting the paper. Again, practice drawing helps a lot with this type of rendering.


The bakery tissue needed some crinkles. I took a photo of crumpled wax paper from my kitchen, and used this photo as a transparency mask for the top bakery tissue layer. I just copied the base layer, dragged it to the top, made it full white, and added the transparency mask. This gave it much more natural looking crinkles than I could draw in a vector design software myself.

Two shadow layers

Since there are a lot of light sources in a diner, I made two shadow layers. One fainter shadow for the upper parts and edges of the bakery tissue, and one darker shadow for the bottom edge of the bakery tissue to indicate that the strongest light source was somewhere towards the upper part of this tabletop. To make both of these shadow layers, I first copied the base layer, and then distorted and bent it to the way the shadows might hit the table just beneath the bakery tissue.


Grease spots (it’s the little things)

OK, so there is sort of a sixth layer on the bakery tissue. When the kind bakery employee grabs the donut with the bakery tissue, sometimes the donut goodness soaks into the paper a little. I added a faint donut shaped spot where this would have occurred on the bakery tissue. It’s just couple of gray shapes with some transparency and blur. I then used the color burn mask to make it look like it was “one” with the paper.

Grease spots in bakery tissue

Grease spots in bakery tissue


I wrote about how to make a map for graphic design here. That post gives the basic steps for using Maps for Creative Cloud as a mapping tool inside of Adobe Illustrator

“Burning” the map into the bakery tissue

To make the map look like it was part of the bakery tissue, I gave it a nice deep blush pink color, and simply added the color burn transparency mask in Illustrator. That is really it! The border layer of the states is just a darker hue of the blush pink color that sits on top of the country as lines. I didn’t use a color burn filter for  the borders, but I added a 5% transparency.


If you read that post about how to make a map with Maps for Creative Cloud, then you know that the labels were downloaded in the map. I didn’t have to manually add them one-by-one. You also read that I reprojected the map from Web Mercator to Albers Equal Area Conic. This projection gives the contiguous United States a beautiful curve that rises on the coasts. I manually adjusted each of the labels to match this curve. I also decided to add the city names beneath the shop names.

Map and Labels incorporated into the bakery tissue

Map and Labels incorporated into the bakery tissue


I wasn’t around in the 1950s, but if you do a google image search for “donut” you will see a lot of pink frosted donuts with sprinkles. So I created that pink frosted donut with vectors and a transparency mask, and now I’m craving donuts. There are four layers that make up the donut. They are stacked from top to bottom in this order:

  1. Sprinkles. Some sprinkle-shaped vectors with a slight gradient overlay and a dark outer glow.
  2. Donut. There is a lot going on in this layer. This has the cake part with a transparency mask made of a photo of pizza dough. It also has the pink frosting, and highlights for the donut as a whole. I also added a secondary shadow to this layer.
  3. Donut base. This is just the part that gives the donut its color, following the same idea as the bakery tissue base.
  4. Donut shadow (bottom-most layer of the donut, just like one of the tissue shadows)


This newspaper is designed with vectors, just like all the other layers described above: there is a gradient that mimics where the light might shine brighter on the paper; there’s a transparency mask to help indicate a natural paper texture; I used shadows to help show where the light sources might be.

Full donut map and illustration.

Full donut map and illustration.

Get Started Creating D3 Maps

JavaScript is fun, and D3 is great.

At Petrichor Studio we like to use D3 for our interactive, web-based visualizations.

As I promised recently, we’ll spend time talking about making maps with this wildly popular JavaScript visualization library.

D3 is sometimes known for imposing a learning curve on dataviz folks and JavaScript developers, but I am convinced that once you’ve tried it out several times–regardless of success or failure–familiar patterns will start emerging in the code.  There are plenty of wonderful resources and blogs that were crucial in helping me begin to understand how to harness D3, and I have included some links at the end of this post in case they might help you out, too.

Below are a couple code samples to help you get started making a simple world map in your browser.  One approach shows you how to render GeoJSON data in your browser as graphics using SVG, while the other approach uses Canvas.  They can be compared side-by-side and I encourage you to identify their similarities and differences.

The overall pattern goes like this

  1. Set up the element that will render the graphics of your map.  Choose <svg> or <canvas> and give it an initial width and height.
  2. Establish the map projection.  We want to make a two-dimensional map, but our geographical features exist on a three-dimensional planet.  We’re going from longitude/latitude coordinates to a flat map and D3 needs to know how that should happen.  Read up on Map Projections in the Web when you’re ready.
  3. Create a D3 geographic path generator and tell it about the map projection.  This is the workhorse that instructs SVG or Canvas how to create two-dimensional graphics out of GeoJSON data.
  4. Load your spatial data.  The samples below use a network request to load publicly available world country geometries in the TopoJSON format.  TopoJSON is more or less a special format of GeoJSON.  It just takes 1 extra step to convert from TopoJSON to regular GeoJSON.  No big deal.
  5. Use the geographic path generator to convert your data into graphics.  The longitude/latitude coordinates will be drawn as map graphics in the <svg> or <canvas> element.

Simple D3 Map using SVG

See the Pen Simple D3 Map using SVG by Jacob Wasilkowski (@jwasilgeo) on CodePen.

Simple D3 Map using Canvas

See the Pen Simple D3 Map using Canvas by Jacob Wasilkowski (@jwasilgeo) on CodePen.

If you are just getting started with D3 the best advice I can give is simply what worked for me: read other people’s tutorials and code samples, all while experimenting on your own until perceived failures become replaced with tiny successes. The tiny successes will become bigger over time and failures won’t seem so scary or annoying anymore.

Good luck! We’ll revisit these topics in more depth by focusing on Map Projections in the Web.

Helpful resources

Formula 1 World Circuits

It’s time to go retro racer in 2018.

Formula 1 screenshot

Check out this animated map of Formula 1 World Circuits!

Even though it is already May, the college basketball excitement and hype of March Madness inspired me to do a sports-related data visualization or mapping project.  It was a lot of fun working with animations for the gerrymandering topic in What’s Your Vote Worth?, and it eventually crossed my mind to explore Formula 1 circuits.

What we do here is stack all the circuits on top of each other, like misshapen pancakes, and show you only 1 at a time.  Even though they’re scattered throughout several continents, here they share the same space and the same map scale.  Then, we continually move on to another circuit by morphing between the current shape and the next shape in the pancake stack.  The world reference map is also updated to provide geographical context.

An argument for doing this (other than just because I can) would be that you can directly compare the circuits’ shapes, sizes, and orientations, without having to find and navigate to each circuit separately as with a traditional web map.

I wanted to style this with an 80’s retro racer vision of a neon, cyberpunk future we’re all speeding towards, so we employed SVG and CSS effects along with an awesome font to achieve the final look.  (Thanks, Sarah!)

The stacking and morphing is all done on-the-fly in JavaScript with some neat map projection and shape animation techniques.  We’ll walk through how D3js and flubber were used to make all this come together in upcoming blog posts.

Fantasy Mapping: Place Names & Design (and free Adobe map assets!)

Several weeks ago, I wrote about a fantasy map named Kystfjell (pronounced kist-fyell, but feel free to say kist-fell), which translates from Norwegian to “coastal mountains.”

In that first post, I mentioned I’d be writing an upcoming Part II that describes some of the design decisions, including place name and language, character illustration, and geographical juxtapositions within the Kystfjell map. I also promised some free Adobe Illustrator libraries based upon this design. So here we go! This is Part II. If you want to jump straight to the free stuff, HERE is a truncated design assets library that I made, inspired by this map. But wouldn’t you want to know the background of those libraries and of Kystfjell?? If so, keep reading.

Important to know: This map was made using the M4CC extension inside of Adobe Illustrator. For information on how, read the first post on this Kystfjell map.

The difference between the actual geography and Kystfjell’s geography

As cartographers, even though we aim for a known level of accuracy and precision, we still are abstracting spatial data to a digestible level. The most obvious example of this is scale. Maps are typically a 1 to greater-than-1 scale – at least the examples we usually think of when we hear the word “map.” Although, consider this beautiful Anatomy of the Teeth poster by medical illustrator, Lydia Sharp. In a sense, Sharp’s poster, and microbiology illustrations like Shannon McMann’s Brain Cell diagram are maps of a 1 to less-than-1 scale. Maps (and dataviz) of all kinds have abstracted the representation to its necessary parts, so that the visualization’s purpose and message can be easily understood by the intended audiences.

When creating the Kystfjell map, although I downloaded real geographic data over coastal Norway at a scale of 1:140,000 (see image below), this map was fantasy. I can move mountains!

And I did. I was not tied to usual intentions of communicating an abstracted reality for the purpose of data comprehension or actual geographical navigation. While I frequently do draw illustrations that have nothing to do with maps, I have never applied the liberty of mapping things where I want to for the purposes of a fantasy map. Kystfjell’s scale is much smaller (the world in the map is much larger than the downloaded data’s actual scale), as a series of large interacting societies. This means that instead of the actual geographic extent’s ~30-40-mile width, my map is about 1,000 to 1,800 miles wide. Although who knows? There is still time for Kystfjell’s geomorphology in my imagination, as the book is still being written.

Data downloaded into Adobe Illustrator using M4CC

Original data downloaded into Adobe Illustrator using M4CC.


Check out this map diagram below. In it, I’m showing the extent of the Kystfjell map, and changes that I made to the data that were included in my original download into Illustrator.

Changes made to the original (real) geography to make the Kystfjell fantasy map

Changes made to the original (real) geography to make the Kystfjell fantasy map

Here is the final land juxtaposition for the Kystfjell map.

Kystfjell Map full (unfinished)

Kystfjell Map full (unfinished)

Overall design of Kystfjell

Please consider the Kystfjell fantasy map unfinished. In fact, I’m not certain that the land will retain the “Kystfjell” name over time. When I get some time to finish it, the first sentence of this paragraph will be deleted. So will the sentence preceding this one, along with this sentence, and perhaps a few subsequent ones. While the map is unfinished, the overall aesthetic will remain. Why am I posting about the design when it is not quite finished? In part I several weeks ago, I promised some free Adobe Illustrator libraries, along with a post about Kystfjell’s design “soon.” Now feels like soon, so let’s talk about design!


There are really five basic colors on this map, and every other color stems from those hues. The sixth color is the highlight color. I don’t know how everyone else thinks about color, but for me, what I call highlight color is essentially just that – the color that all other colors travel to as they get lighter. So if you can imagine a gradient for each of the base colors, where the darkest hue in the gradient is the base, and the brightest hue in the gradient is the highlight color, then you can imagine that the colors within those gradients are fair game for the particular project. In most of my work – maps and other illustrations – the highlight color is almost never basic white. This retains rich tones throughout the illustration. With every map I make, I try to keep the colors at a minimum, so I made swatches of about six or seven colors within each of these gradients and only drew from those colors. I use this color method for a lot of things that I do, but when it comes to mapping for customers with specified style guides, I’m often bound to a basic strict small group of contrasting colors and/or complimentary colors. But not for Kystfjell!

Kystfjell Base Colors

Kystfjell Base Colors


The mountain base color-to-highlight color gradient.

The mountain base color-to-highlight color gradient

You can find the Kystfjell base colors and other Illustrator Assets here, where I’ve shared them publicly. Notice how the colors look much flatter and more saturated than they do on the map. Recall how I’ve created gradients from each of these base colors to the highlight color (image above this paragraph), and from that gradient, created a palette made from those gradients. Doing so gives the map some depth. Also, I’ve added some transparency masks explained below.

Kystfjell Assets

Save these free assets by clicking on the image


I was able to apply a papery texture to the Kystfjell Map by using Adobe Illustrator’s Transparency Mask option. This post isn’t going to include a step-by-step tutorial on how to use transparency masks in Illustrator, but perhaps such a post as it relates to cartography is called for in the near future. It is just important to know that this is how this map was textured. There are a lot of great YouTube videos and online tutorials provided by designers that share how they use transparency/opacity masks. But here is a tiny window into my particular approach to how I used a transparency mask to achieve a papery look in the Kystfjell map. Ultimately:

  • There are ten layers listed below that make up the entire land-plus-ocean base of this map, and one more that makes up the shorelines (see next section for the shoreline creation).
  • Each of these ten layers has some sort of Illustrator effect (not necessarily capital “E” effect, or what AI considers an effect). By this, I mean each of these ten layers has a permutation of gradients, transparency masks, and inner glows; at least one of these effects, but perhaps two or all of them.
  • By removing any one of these ten layers, the entire base’s aesthetic would change, either slightly or dramatically (see animation below for how stacking these layers changes the base’s look).
  • This approach is certainly not necessary, but I’m really happy with the result.
Kystfjell Land and Ocean Layers

Kystfjell Land and Ocean Layers

Of the layers inside my Land and Ocean Layers above, the following have a transparency mask applied. The mask was made from a photo of crumpled paper:

  • Highlight Ocean (Also using the Lighten filter within this transparency map setting).
  • Darker Pink Land with Gradient
  • Land Color Burn (Also using the Color Burn filter within this transparency map setting).
  • Bottom Ocean Layer

When applying a paper texture to a transparency mask on multiple layers, one trick I like to use is to make sure that the paper texture image is the same one for each layer and the X, Y registration for this image is identical each time you paste it. Copying artwork and pressing CTRL + F / CMD + F will paste artwork in the exact X,Y registration in front of  your other artwork in a layer, and CTRL + B / CMD + B will paste it behind your other artwork to whichever layer you are pasting.

Stacking the 10 ocean and land layers and the shorelines layer

Stacking the 10 ocean and land layers and the shorelines layer

Concentric Shorelines

I applied a concentric shoreline effect to the land shapes using the Object –> Expand –> Offset Path method that I wrote about on this previous blog post. Note* That previous post addresses making concentric shorelines from a linear (unclosed path) feature, such as a shoreline that falls completely off the edges of your map (Object –> Expand). I applied the remaining principles from that post’s approach to Kystfjell’s concentric shorelines.

Kystfjell map shorelines

Kystfjell map shorelines

Whimsically hand-drawn

I wanted the Kystfjell elements to appear whimsically hand-drawn. To avoid a clean digital look I used brushes from the Artistic_ChalkCharcolPencil brush library that is provided with Adobe Illustrator, as well as a few other brushes. You can see some of those brushes applied in these complimentary graphics that I’m sharing here.

Language and Placenames

Each aspect of this map was an adventure: location scouting, character developing, mountain drawing, and place-namingAs stated previously, this is my first fantasy map, so creating placenames was unexplored territory. I wanted the names to be of Norwegian influence as a nod to my heritage, but also easy for an English speaker to read. Some of the names are combinations of Norwegian words, or combinations of Norwegian and English words. And some locations are English words. I wanted Norwegian readers to read the names as actual names as well, so I consulted my friend that I have known since middle school, Benjamin Nelson. Ben is fluent in Norwegian, lives in Norway, and is married to a Norwegian woman, Linn Monica. They reviewed the placenames to ensure the names did not get translated as garble to a Norwegian reader. Also, it was pretty important to me that I wasn’t unintentionally using a word that was crude. Many thanks to Ben and Linn Monica for their review of the Kystfjell map placenames!

The Future of Kystfjell

It is true! Kystfjell is a place in a story that I am writing! As the story gets written, the map is sure to change and characters are sure to be added. I anticipate that I will generate many maps and illustrations as the story moves forward.

I’m always excited to see the fantasy maps that others are making, as well as read about the stories that inspired those maps. Please share yours if you’d like! And happy mapping!

Me making the fantasy map

Hey, it’s me with Kystfjell in the background. Action shot! Whoa.

Happy National Beer Day! Bellingham Bike Shops & Breweries Map

It’s National Beer Day this Saturday, April 7th! I’m celebrating by posting this Bicycle to Breweries Map of Bellingham, my home city.

National Beer Day is a great excuse to share this map, but I should probably give at least a brief description of the map.

The map shows the location of the city’s breweries and bike shops nearby. I made it using the ArcGIS Maps for Adobe Creative Cloud extension, and its entire dataset comes from the City of Bellingham’s open data. The streets marked with a red dash are all part of Bellingham’s Pedestrian Master Plan, which is an ambitious infrastructure program to improve the City’s walkability.

Bellingham is already wonderful place to walk and bike, rain or shine. The city has great trails, great breweries, and a lot of cyclists, walkers, and runners. With late night sunsets approaching, the season for riding bikes to neighborhood breweries is coming soon. I started this map as a tutorial to show fellow mappers how to make a map using this particular Adobe Illustrator extension, made by Esri (I’m on that team!). One of the features in the extension’s latest updates is the ability to pick from standard layout sizes for print, mobile, and other common media formats. This map uses the 11×17-inch tabloid format.

I am going to file this map into the permanently unfinished category. However, it will certainly help you find the Bellingham breweries, most bike shops, park-and-rides, all traffic lights and trails that were in existence during the time the data was created. It also was a fun exercise in creating a Victorian-esque Adobe Illustrator symbol set.


Bellingham Beer & Bikes Map by Sarah Bell


NCAA Basketball: Who’s Come the Farthest?

If you visit ESPN’s website, you can find the team rosters for all the NCAA Basketball teams that made it to the NCAA tournament. On that site, ESPN lists the players’ number, position, year, and hometown, among a few other statistics. A couple of my colleagues, Nick Brueggemann and Gregory Brunner, did some mapping with this data. I asked them if I could take their dataset and crunch it a little further. There is a ton more that could be done with this information. And maybe I will someday, but here’s what I have done for now to spatially visualize the NCAA D1 Basketball Tournament team roster data:

I decided to map the women and men athletes’ hometowns as graduated symbols, where hometown sizes are based upon the amount of athletes that come from there. The men and women hometown maps are separated in order to more easily identify the different locations. These maps started out with world city points and labels, but I removed them for the sake of decluttering the visualization. I was able to identify the lat long of the athletes’ hometowns using ArcGIS. I then calculated the distance from each player’s hometown to the city that their team is located; here is a really handy blog post that someone wrote eleven years ago; I often refer to that post when calculating distances between lat long coordinates. Calculating the distance of each athlete’s hometown to their team city allowed me to identify the average recruit distance per team, along with the farthest (and closest) recruit distance. Other than the maps themselves, I haven’t done any visualization for teams on the lower end of the average recruit distance. (Maybe in few days ?) There are a lot of players whose hometown is also the the same as their team’s city.



“Bring Up State” Animation Effect with D3

*Check out our What’s Your Vote Worth? data viz storytelling to see this effect in action.

Tired of falling down into web maps?

Zooming in, zooming in, and zooming in from outer space down to the Earth’s surface got you feeling sad?

Here’s another idea: demand that geographic features come up to you. Web maps typically require you to zoom in and may give the sensation of “falling down” or “diving in” towards the Earth’s surface. Why not make this everyday interaction become more user-focused?

Click on a state to get started.

See the Pen Bring Up State – D3 by Jacob Wasilkowski (@jwasilgeo) on CodePen.

In this JavaScript code sample written with D3js, called “Bring Up State”, we serve—provide, give, deliver—a state polygon that has been clicked on to give it full focus. This is the opposite from expecting your audience to freely zoom in as with traditional web map experiences. This sample goes one step further by fading away the remaining states in the background to alleviate visual clutter and bring attention to the current state. Take a look at the code to see how it is all glued together.

Just click—no need to fly down closer to the Earth—and the visualization will do the heavy lifting of bringing up the geographical feature directly to you.

Creating a Satin Waterbody Effect in Adobe Illustrator (tl;dr: inner glow!)

Each style decision a cartographer makes on their maps’ features will contribute to the holistic ambience of the map. For example, a map’s tone can change in an instant just by switching typefaces. You might have even had one of those revelatory moments when a typeface gets changed accidentally in flash of serendipity, and suddenly your map has an updated fresh style and direction.

Color choices, amount of colors, graphic design effects, line weight, and a lot of other things in addition to typeface choices are among the decisions that a cartographer makes to achieve – or discover – a particular ambience in their maps. Cartographic water styling is one of these effective ways to achieve a map’s overall mood. In this post, I’m going to give some quick steps to achieve a satin waterbody look in Adobe Illustrator. It’s super easy and fun, and I’ve been doing it for so long that I sort of took it for granted. However, in the few years that I’ve been sharing my maps publicly (I’ve presented on my tendency to be a hermit of sorts) people have asked “How did you do that water effect?” It is invariable that at least one person will ask this question after I’ve presented or posted a map that has this waterbody effect. It’s also a guarantee that I will be excited to chat about it since it is likely that I will also learn from the questioner while sharing with them this water technique.

A small snapshot of an in-progress map I’m making that uses this waterbody technique

There are so many layers with their visibility turned off in this map because it is only about 40% complete. Sharing still, because this map is the one that the Skype call stems from.

Due to the combination of taking this water effect for granted and having some hermit propensities, I had almost convinced myself that it wasn’t worthy of posting about this technique. But after scheduling a Skype meeting last week to discuss this very technique after someone saw a map I shared on Instagram, I decided, “Why not?” So here are some simple steps to get a satiny water look for your maps in Adobe Illustrator. This post focuses on open water, or water that is not fully inside the map extent (i.e. the waterbody is a very large part of the overall map, and is cut off by the edge(s))

Some of these steps will not be necessary depending on your map’s water data.

*TIP! If you are not dealing with open water in your map, but rather your map has waterbodies that are fully inside your map’s extent, like the lakes in my map above, then you can SKIP TO STEP 4. tl;dr: It’s the Inner Glow Effect!

1. Ensuring your land and water polygons are well aligned

A map’s land data doesn’t always align perfectly with water data shoreline. The cause for the mismatch could be that the data sources are different, or that they were created for different scales. Whatever the cause, it doesn’t matter, because you can fix the misaligned polygons with Adobe Illustrator’s Pathfinder tools. In the interest of brevity, I’ll just focus on the most common scenario that I encounter with mismatched land/water polygons.

In the AI file below, I have a Land layer and a World Ocean layer. However, the World Ocean layer was created for a much smaller scale than my Land layer, so it has way less detail, and the mismatch is pretty atrocious.

Check out Orcas Island (large island in the center of the image below), and the white gaps around it indicating the difference between the water and land layers. The detail of the World Ocean layer is so much less than the detail of the Land layer that the World Ocean layer doesn’t even include Waldron Island to the northwest of Orcas. For the best results of the satiny open water look, I like to have all the land details including these tinier features like small islands in the effect at first. If somewhere in the process, these smaller features become an issue to the aesthetic, they are easy to remove.

Small scale ocean data with large scale land data

Orcas Island: Small scale ocean data with large scale land data

2. Creating your own Open Water!

If your open water polygons are perfectly aligned with your land polygons, then this step will not be necessary, but the next step will.

Because my land and open water polygons are not well aligned, I’m going to create my own open water polygon inside of Illustrator. In fact, I’m just going to delete my World Ocean layer, but hang onto your original water layer if you think you might need it for reference later on.

To create a new layer in Adobe Illustrator, just click the “Create New Layer” icon at the bottom of your Layers panel. Drag this new Layer beneath the land layer, and name it whatever is appropriate. I’m going to name mine “Salish Sea” since this is the encompassing term for all the inlets, channels, bays, and sounds that make up this water body.

Now you’re going to want to draw a rectangle in your new waterbody layer that is larger than the land that makes up the shoreline. So click the Rectangle tool, or type the letter “M” for the keyboard shortcut to get the Illustrator Rectangle tool, and draw your polygon. See the video below for how to do this.

Creating the new waterbody


3. Clip your new Waterbody to the Land

Ah, the joy of Illustrator Pathfinder tools. Before you clip your waterbody to the main land layer, you’ll have to make sure that all your land is in one path. To do this, you’re going to use the Unite Pathfinder tool. If you have only one polygon (closed path in AI) then you should be ok. Since my land from which I want the satin waterbody effect to emanate is comprised of several islands, a mainland USA polygon, and a mainland Canada polygon, I know for certain that I need to Unite my land shapes. These shapes must be closed paths! Double check this before moving forward.

3A – Unite the land polygons

First duplicate  all the land polygons layer(s) – there could be multiple – that you want to use for the satin waterbody effect. If there happens to be more than one layer that you are duplicating, make sure to put all the artwork from the duplicated layers into one single layer before uniting. With all the closed paths selected in this new duplicated layer, click on the Unite Pathfinder tool. If all your paths are closed, this will cause polygons that are touching to be merged into one single closed path, and will put all the paths, including islands, into one discrete clipping path. Check out the video below (*note that after clicking the hamburger menu, the “Duplicate Layer” option was not visible, but that is what you will choose).

Uniting your land polygons with the Unite Pathfinder tool

3B – Subtracting land area from waterbody

This easy part in bullet form. Here we go!

  • Unlock the waterbody layer
  • Hold the Shift key to select the artwork in the duplicated land layer and the artwork in the waterbody layer simultaneously.
  • Click on the Minus Front Pathfinder tool. This will punch a hole – or several holes – in your waterbody rectangle that are the same shape as your land.
  • Since all the paths from this action will be brought up to the top, drag the artwork down into your waterbody layer, and delete the empty layer that once held your duplicated land path.s

Watch this video for the quick version:

Subtract land from waterbody path

4. Adding an “Inner Glow” effect

I’m not quite sure why I used quotations around ‘inner glow’ because that is exactly what it is called in Illustrator. This is the actual step where you create a satiny look. However, steps 1-3 are usually necessary when you’re dealing with open water in your map. Again, in bullets, followed by a video:

  • Lock your land layer
  • Select the artwork in your waterbody layer, and go to Effect –> Stylize –> Inner Glow
  • Set Mode to Normal, and check the Preview box.
  • Then just play around with the glow color, opacity, blur until you’re satisfied.


Creating a satin waterbody look with the Inner Glow effect in Illustrator

Your map. Your style.

The great thing about this satin waterbody effect is that it doesn’t tie you into one particular style. It is used by many cartographers in a variety of design styles. In addition to my map in the intro for this post, here are some maps I’ve made that use this satin waterbody effect that each have a very different ambience: Mid-Century; Art Deco, and somewhat of a play on Victorian era styles.

Mid Century style Minneapolis coaster map

Minneapolis, Minnesota square map

Simple square mid-century style map created for NACIS 2015 demo, Minneapolis, Minnesota. Most of the artwork in this map is very flat. The water has a slight application of inner glow to give it more of a satiny feel.

Art deco buildings in Montreal in an art deco style

Map created for NACIS 2017 presentation showing all the Art Deco buildings near the conference. I really wanted to capture the saturated and deepness of what Art Deco styles make me feel.

University of Washington brewery map (also uses concentric shorelines effect)

University of Washington demo map. For the water color here, it is actually a pale bone color, and any blue in the water is coming from the color I applied while adding the inner glow (step 4).