Taking Dashboards from Good to Great with Custom ShapesBy: CoEnterprise | October 6, 2015
Many people struggle with bringing graphic design elements into their Tableau dashboards. Last week, we focused on building better dashboards using custom color palettes. This week, let’s dive into best practices for using custom shapes to enhance your Tableau visualizations.
What image file type is best?
When you perform a search on the internet for icons or shape files, typically you will have multiple file types returned: BMP, GIF, JPEG, PNG, and TIFF. Tableau can use all 5 file types, however PNGs (portable network graphics) should be your go to for two key benefits.
PNG Benefit #1: Transparent Background
On a white background, you do not notice the difference between a JPEG shape and a PNG shape. It’s only when the shape is placed on a colored background that it becomes obvious why to use the PNG. PNGs have a transparent background which allows shapes to be placed on any color background without concern of an ugly white square around the icon.
Often, we need shapes to appear in close proximity to other shapes in view, overlapping at their edges in certain scenarios. Because PNGs have a transparent background, they can be arranged close to each other without concern of the background overlapping a neighboring shape. With JPEGs, the background will overlap eventually, causing undesirable effects.
Furthermore, if you use JPEG shapes on a map, you’ll be able to see the background white space quite prominently. PNGs reveal elements of the underlying map in a cleaner fashion since their backgrounds are transparent.
PNG Benefit #2: Receive Color Encoding
In Tableau Desktop, if we use JPEG shapes and add a field to color on the marks card, the entire rectangular area of the JPEG is colored, not just the icon. One-color PNGs receive color encoding as we expect since their background is transparent.
Where can I find high quality PNG libraries?
My go-to is always the Noun Project simply because I love the concept. They are an open-source global initiative whose mission is to develop a freely accessible library of icons that will translate across all cultures and languages as a visual language. The site welcomes and encourages contributions from around the world and hosts “iconathons” to encourage constant growth to their libraries. Thanks to the Creative Commons license, most are available for use in Tableau or other mediums. To get started, simply search by buzzword, scroll through the library results, and save those you want to your machine (right-click icon preview and select “Save Image As…”).
I maintain a list of other equally wonderful icon libraries on the internet. Make sure to check out the links below for millions of icons available for free.
What tools can I use to build my own PNGs?
My go-to tool is Adobe Illustrator but you can use PowerPoint as well. Yes, PowerPoint can build PNGs. Any shape, textbox, smart art, or element in PowerPoint can be saved as a PNG by right-clicking and selecting “Save as Image.” I use this most often to convert text to images when sending PowerPoints to my team (as I tend to use some non-standard fonts). It also comes in handy when I need to preserve text on a dashboard that is an unsupported font on Tableau Server. Changing specialty text to image prevents the text from returning to a substitute font when they open the file on their machine or device. The same functionality can be used to bring in images and icons to Tableau for marks, highlights, logos, drop shadows and buttons.
To convert PowerPoint graphics to PNGs for use in Tableau, follow these simple steps:
- In PowerPoint, right-click the shape or text element you want to convert to PNG.
- Select “Save as Picture…” from the right-click menu.
- Name the file and choose a save location. The file type will default to a PNG.
What file size is best for PNGs?
The file size will depend on the visualization. Resizing of the shapes is limited in Tableau as the size slider (Size button on the Marks Card) has a predefined range. I tend to save three versions of my PNGs to have a low, medium, and high resolution option. Icons should never be smaller than 32 pixels by 32 pixels. I tend to save a 50×50, 125×125 and 250×250 version.
How do I add custom shape palettes to Tableau?
Once you have identified the icons you want to use, you’ll need to save them to a very specific location on your computer. Browse the “My Tableau Repository” (available to PC users in your My Documents folder). Think of the “My Tableau Repository” as Tableau’s brain. The software looks here for color palettes, log files, map sources, data sources, and more. Double-click the “Shapes” folder inside the “My Tableau Repository” and you’ll recognize that the list of folders within is the exact same as the shape palettes available by default in Tableau.
To create a new shape palette, add a new folder within the Shapes folder (don’t forget to name the new folder). Inside the new folder, save (or copy) any of the images you want to utilize in Tableau. The next time you open Tableau Desktop, your shape palette will automatically load. If you have Tableau open while adding shapes, you can either save and restart Tableau, or use the “Reload Shapes” button from the Edit Shape menu to refresh the available shape palettes.
Remember if you are sharing your work with others through Tableau Server, you’ll either need to save your workbook as a TWBX (packaged workbook) or ensure your server admin has added the same shape palette name and contents to the Tableau Server’s repository.
Jedi Mind Tricks (Advanced Use Case for PNGs)
Sometimes we need to show worlds of information in very small spaces. Think about the process of finding a new home. We search by price, but just as important are the number of bedrooms, number of bathrooms, garage size, square footage, and school district. That is a ton of information to show in one view, however we can combine a few key metrics using iconography and place the other details in a tooltip. By utilizing PNGs, we can take advantage of the transparent background to overlay multiple icons into one informative graphic.
I hope these quick tips help you to think outside the box of the shapes available in Tableau by default. There are multitudes of free sources to enhance the user experience. Adding iconography ensures the data translates to all users (no concern of shape deficient users like we saw with last week’s color palettes). Remember to always check your work across multiple devices (iPhone, Android, etc.) as well as to use the smallest image size needed.
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