1. How to start blending shapes
The most basic thing you can do with the Blend tool is to blend one shape into another across a specified number of steps. Draw a circle, hold Opt/Alt+Shift and drag it across the artboard to create a duplicate.
Now select both shapes and go to Object>Blend>Make (or hit Cmd/Ctrl+Opt/Alt+B) to create a blend between the two. Illustrator will produce a default blend, which might not be what you want. So to edit it, keep the blend selected and double-click the Blend tool icon in the toolbar. Select Specified Steps and change the value.
If you tick the Preview checkbox you'll be able to see the effect the value has on your blend instantly. Be aware that blending works on both filled and stroked shapes, as well as those using transparency, making it a really versatile tool.
2. How to use the Specified Distance option
The second way to blend is via the Specified Distance option, which does exactly what you'd think and spaces out the steps by a specifically chosen distance between each one, rather than by defining a particular number.
This can be useful for making perfectly measured diagrams or bar charts, for example, where you need elements to be equidistant from one another and to adhere to a predetermined grid.
3. How to use 'Smooth Colour'
Smooth Colour is a slightly different option and creates a smooth, filled blend between your two objects. This is useful when looking to create particularly intricate gradients or cloth-like effects.
As before, create two shapes - but this time give them two different colours and blend as before. In your editing options, this time choose Smooth Colour and click OK. You'll see that rather than blending in steps, a continuous block of colour has been produced to link one shape to the other.
4. Master the 'Replace Spine' option
The Blend tool becomes really interesting when you start to use the Replace Spine option to create blends on a path other than a standard straight line. Draw the shape or open path that you'd like the blend to follow, and select it, along with your previously made blend. Go to Object>Blend>Replace Spine.
You will see that the blend has now attached itself to your new curve, making an interesting effect. When editing your blend, be mindful of which aligning option you choose (Align to Page versus Align to Path) as both will give significantly different results.
5. And finally...
Be aware that you're not just limited to blending two objects. You can create a blend using as many different shapes, colours and transparencies as you can think of.
This tutorial was originally published in Computer Arts magazine. Did you find it helpful? What other Illustrator tutorials would you like us to publish. Suggestions in the comments box below please.