Tableau maps are quick and easy to make. Just a few double clicks and your data is displayed geographically. But with a few quick tweaks, you can make your maps even better at displaying your data. Here are 4 easy things to do to make you maps look more readable.
1. Change the background color
Depending on what color scheme you are using, some marks are harder to see on the default gray map than others. I find that when I'm using a diverging palette, anything in the gray/white area in the middle fades into the background map. It's easy to fix this problem; just change which map you are using! In the menu click Map>Map Options. Under "Style" you'll find two other background maps to use: normal, which has green land and blue water, and the dark map, which had black land and dark grey water. I find that especially when using shapes on a map, dark maps work the best.
2. Hide unnecessary layers
When you are working on your map, stop and ask yourself "Are all of these borders and labels important?" For example, if you are making a map with data based on country, you probably don't need state and province borders and labels. Removing as much clutter as possible removes potential distractions from your data and makes everything easier to read. You can turn map layers on and off in the Map Options menu by clicking the checkboxes. You may notice that some of them are grayed out; map options become available when you are zoomed in enough to see that level of detail.
I often find that I don't need any map layers. For example, when I'm making a filled map of US states, I don't really need any map layers. The audience that I'm sharing this viz already knows where the US is geographically, and the states are filled, so they don't need any additional outlines. You can see that in the image above, I don't have any background maps at all and it lends itself to a very clean design. You can get rid of everything in the map, as I did above, in the Map Options menu by setting Washout to 100%.
3. Float pieces of the map to make everything fit better
When you see maps of the United States, it is not uncommon to see Alaska and Hawaii floating in the middle of the Pacific ocean. Map designers do this to save space; to display Alaska in context, you end up wasting a lot of space showing all of Canada and to show Hawaii in context you have to span quite a bit of the Pacific ocean. You can use Tableau Public's ability to float objects on a dashboard to replicate this space saving technique. Just duplicate your map twice: once for Alaska and once for Hawaii. Then you can zoom in on the appropriate state in each map. When you bring them into your dashboard, you can float them in the white space in the Pacific ocean. When you combine this technique with removing all the background maps, you get a very clean design.
Another tip for when you have multiple maps of the same data: if you click on a state in one of the maps, highlighting won't necessarily work in the other parts of the map. you can fix this with a dashboard highlight action. In the menu bar go to Dashboard>Actions and create a new highlight action. Select your three maps as both the source and the target. Now, your maps will highlight like one map!
4. Use the built in data layers
If you are making a map of the US, using shapes, and want to convey extra information about the demographics of the areas you have mapped, you can take advantage of Tableau's built-in data layers. These layers are only available in the classic styled Tableau maps, so first you'll have to go to Map> Background Maps>Tableau Classic. Once that is selected, you'll find the data layers at the bottom of the Map Options pane. You can choose which demographic to show, what level of detail you'd like to show it at, and what color palette to use. Data layers can even use custom color palettes!
Have any other mapping design tips? Make sure to share yours with the hashtag #MappingMonth