Paul Butt loves creating infographics documenting popular culture, as he believes a strong relationship between the viewer and the content is a great thing to have. Inspired by the Guardian Datablog, which had documented the appearance of every monster in Doctor Who, Paul decided to make a graphic about the TV show’s most feared enemy – the Daleks – and give some tips and techniques on how to produce stylish and intelligible infographics.
This tutorial is about creating a circular-style bar graphic using basic Illustrator techniques. You’ll also learn about a few shortcuts to streamline the procedures and avoid future problems.
Time to complete
Under an hour of practical work; most of the time goes into preparation
Adobe Illustrator CS3 or later
Preparation and planning is key. I try to sketch out any idea before picking up the mouse. For this graphic, I liked the semi-circular-shaped head of the Dalek and thought it would be a good effect to wrap the data around it. Splitting up the data by Doctor seemed the obvious choice.
Create a new document in Illustrator: 200mm square at 300dpi in CMYK. In the View menu, turn on Rulers (Cmd/Ctrl + R), Grids (Cmd/Ctrl + “) and Guides (Cmd/Ctrl + ;). In Illustrator’s Preferences, set the grid to lines every 5mm, with 10 subdivisions.
Drag vertical and horizontal guidelines into the exact centre of the artboard, then click and drag from the top-left corner of the rulers to the centre of the artboard.
Select the Ellipse tool (L) and click the now-clearly-defined centre of the artboard whilst holding Alt. Enter in 120mm for each value and click OK. Do the same for a 50mm circle, then select both and use the Minus Front shape mode in the Pathfinder panel (Cmd/Ctrl + Shift + F9) to create a doughnut.
Draw a rectangle two grid-segments wide (1mm) that starts from the centre of the artboard to just past the top of the doughnut. This will be our separator. With it selected, press R for the Rotate tool and click on the centre of the artboard while holding Alt. Enter 20° and press Copy.
Now press Cmd/Ctrl + D to duplicate the lines round the circle until they match up. Select all the rectangles and use the Unite tool in the Pathfinder panel to merge them into one object. Then select both the doughnut and the new star shape and use Minus Front as before.
We only need 11 segments for the 11 Doctor Who actors, so rotate the whole group of bars 10 degrees around the centre so that two of the breaks sit exactly horizontal, then delete the bottom seven segments. This creates our basic frame.
Create a data scale on a new layer using the Line Segment tool (\). You can save time by creating one section and duplicating it.
Duplicate the original layer of circular segments by moving it in the Layers panel whilst holding Alt. Fill the top layer with a solid colour, as this will be our data layer.
For each segment, draw a circle from the centre of the artboard holding Shift and Alt to constrain proportions. Make sure you have Snap to Grid (Cmd/Ctrl + Shift + “) turned on and size it according to the value. Then select both the circle and the segment and right click > Make Clipping Mask.
Repeat Step 9 for all segments. The temporary scale can now be rotated to the end of the part-circle, having done its job in helping us build the graphic.
Create label boxes for each segment using the same method as in Steps 3-6, but creating a larger doughnut around the outside of our existing segments. Add a coloured background, and colour your elements if necessary. As it’s a description of history, I’ve gone for quite a retro colour scheme.
Create a circle from the centre of the artboard that runs out to the label boxes. Then use the Type on a Path tool to create labels. Double click the tool in the toolbar to change alignment options. When you’ve done the first one, you can rotate and copy it 20 degrees to create the rest – then go about editing the names afterwards at your leisure.
Use the same technique to create the data labels – in this case, the number of TV episodes. Resize each one in turn so they sit one grid mark above the relevant bar.
When you do this, the font size will change, so it’s best to align the type to the Baseline. You can then adjust the font size of the whole layer at the end without them shifting position.
To create the underlying ripple effect that aligns with the scale, create a centre-aligned circle that goes to the edge of the scale. Fill it with a radial gradient with white at the 90% position and black at 100%. Then make copies staggered inwards every 5mm. Finally, select the layer and set its blending mode to Lighten and its opacity to 10%.
To create the diagonal stripe pattern that sits between the bars and the names, draw out a square then duplicate some diagonal lines on top. Expand and group the lines. Use Intersect in the Pathfinder panel to trim off the excess lines, then drag the group into the Swatches panel to create a pattern fill that can now be applied to any object.
From here on, it’s really a case of adding in more layers of detail and information using the same basic techniques. The Dalek was drawn with the Rectangle and Ellipse tools. I also added titling and a key and some textures to break up the solid colours and ‘grunge it up’ a little.
Paul is a freelance graphic designer with an interest in infographics and data visualisation. His work is usually split between magazines and corporate communications. He has worked on behalf of clients such as Wired, the Financial Times and Skype.