Contributor & Author: Tiffany Spaulding
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 Power
Points 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 50x50, 125x125 and 250x250 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.
