A Cartographer's Toolkit

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Today I’m thrilled to publish this guest post by the extraordinary freelance cartographer Hans van der Maarel of Red Geographics. He’s also the administrator of the Cartotalk forum and you can follow him on twitter via @redgeographics. He’s from The Netherlands.
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I’m a mapmaker. I love making maps, I love looking at them and I love talking about them. I’m also a cyclist. I love riding my bike and I love talking about it. Sometimes I get to combine the both, for example when I’m taking part in an organised ride – or when I go watch a cycling race to combine it with my other hobby, photography. Of course I want to know where I’m going to ride (or where the best spots for photos might be), so I check the event’s website to see if they have a map.

The one thing that bugs me is the fact that in many cases, the ride or race organisers made a map by simply taking a screenshot of Google Maps and adding some information (lines, points, arrows, notes) to it in Paint. It does the job, yes, but it’s not pretty and it may not even communicate the right message. What’s even worse is that sometimes even large public or private organisations do this. Maps are often added as an afterthought.

Of course if you’re reading this it’s quite likely that you’re producing maps yourself, so you don’t go for the Google Maps technique. Instead, you work, obviously within the constraints of your time and budget, to make the best map you can. You collect the required data and make a nice design – you pick colors and styles and finish the whole thing with legend, scale bar and all the other map paraphernalia. But a map can be much more than just a pile of data with some visualisation rules applied to it and I would like to urge you to spend some more time on the design phase, because it matters. In a guest post on visual.ly Daniel Huffman argues that cartographers are storytellers. A map is a story and spending a bit of time to consider the message you’re trying to convey can really improve it. By consistently delivering high-quality, well-designed maps we can prove our worth as cartographers and promote maps as a legitimate and valuable form of communication.

So here’s some general tips:

• Know the story you’re trying to tell.
• Consider your audience. What can you expect them to know? Make sure you tailor the map to them.
• Understand your data, make sure you use data suitable for the scale you’re working on. If it’s too detailed, or not detailed enough, try to find something better. Also don’t be afraid to manually redraw things to get a better looking end result. You don’t always have to use data, cartograhpy is after all an art form. Don’t be afraid to let go of geographic accuracy if it will improve your storytelling.
• Consider your styles. Look at the map from a little distance and check whether the things that stand out are in fact the things you want to stand out. Also make sure you don’t do things that your output media can’t support. I once had to make maps that were to be printed on fabric, this meant pure white was off limits because the fabric would shine through at those spots and the minimum text size was 8 points, whereas on paper you can often go as small as 5.5 points.
• Consider your map content. For every data layer that you add, ask yourself whether it’s really necessary. This also goes for map paraphernalia such as north arrow, scale bar and legend (yes, even a legend can be optional, and labeling a legend as “legend” is quite unnecessary). Edward Tufte wrote an excellent book on this subject: “The Visual Display of Quantitative Information”, I can highly recommend reading this.
• Consider your texts. Are you using the right font? Are they big enough, but not too big?
• Consider whatever is going on around the map. A big pet peeve of mine is reading about towns A, B and C and only seeing D, E and F on the accompanying reference map. If your map is going to be part of a larger layout, see if you can get a mock-up of that to work off. Of course you also need to coordinate font and color usage.
• Get inspired! Either by collecting (images of) maps that you think are really well done or get exposure to art and design through some other way (visit a museum for example).

The ultimate goal of this is to produce a design that’s balanced and gets the message across without containing too much information that might confuse your map readers. It’s not easy, or even possible, to come up with a value estimate for good design and sometimes you’re simply not going to be able to spend as much time on it as you want because of budget and/or time constraints. Or you don’t always have a say in the final design of the map. The person you’re designing it for may have something to say about it as well, and sometimes their views contradict yours. Still, you should endeavour to do as good a job as possible within those limitations.

If you’re looking for inspiration I can highly recommend the NACIS Atlas of Design, as well as the Cartotalk forum.