How to use the blend tool in Illustrator CC 2017 2015 2014 CS6 etc
The key thing for the blend tool is to select two paths (or more) but two is fine to start with.
1) Create path
2) Create another path - perhaps a copy of the first path
3) Select paths
4) Go to the blend tool in the toolbar
5) Click the first and then second path with the blend tool
And there you have your first blend
Double click the Illustrator blend tool in the toolbar. You can set the settings before you create the blend or at any time afterwards for a particular blend combination as it is a live effect.
You will see only a couple of settings such as smooth color and specified steps and the number of steps and specified distance and the distance as well as align to the page and align to the path.
Personally, I generally use the number of steps but specified distance is great if you want to create a blend with paths added say every 10pt or 100pt etc. The smooth color is probably the easiest but least useful (for me) tool but say you have a blue circle and a red circle blend then then blend is between blue to red which can be useful in all kinds of smooth colorful designs such as creating highlights for a sphere design etc.
The key thing to remember it is always live and can be changed at any point
Once you have applied the blend, you can still alter the paths involved in the blend such as changing the shape of the paths or perhaps changing the color of the paths and that can be done by selecting the path using the direct selection tool and then changing the color or shape etc for that path or perhaps removing or adding points etc.
There is also a blend tool path / spine (not the paths used in the blend but the line between the paths) and you can also use the direct selection tool to select that spine path and then shift the spine path and distort the spine from the initial straight line.
You can also then use tools such as curvature tool or use the anchor point tool to manipulate that blend spine.
You can then use it to create some truly unique blend paths with the blend tool and it is still all live and the steps and smooth color etc can still be changed in Illustrator.
There are also a number of blend tool Illustrator menu commands which can be found via the object menu and blend
Reverse front to back
They are all super useful. The replace spine is probably the most useful with the Illustrator blend tool and to use that select the blend as well as another path such as a spiral open path and then go to the replace spine command and then the blend will be attached to a spiral etc. Or select the blend and select a circle (closed path) and then use the replace spine and you will end up with the blend around a circle which is great for creating all kinds of circular frames etc.
The reverse spine swaps the spine around so if you have a red large path at the start of the blend a small blue path at the end, use the reverse spine and the small blue path will be at start of the spine.
The release just removes the blend - which is the least useful feature perhaps as you can always just undo or delete the blend (but the release just leaves you with the original paths)
Expand - expands the blend tool to normal paths
You can create many different and interesting blends with the tool and type. Select two or more and the type doesn't need to be same so you can have some type with the letters 'xyz' and also some letters 'abcd' and blend between those and also with different colors.
The type and the blend are all live and can be changed at any point in the process so if you decide to change the words from 'topic' to 'some other topic' you can and then you will see the change in the blend
You can create all kinds of zoom and weird and wonderful twisting type effects by using the blend tool in Illustrator
You can quickly create all kinds of frame designs with the Illustrator blend tool by creating one blend and then duplicating that and then dragging the artwork apart and then clicking the two ends of each of the blend spines and additional blends will be generated between those two original paths to create a square frame artwork in seconds such as displayed below
You can add the blend tool results into the CC libraries as well as using them as a great source for symbols etc by adding the artwork to the symbols panel and then you can use the artwork as a great source of designs using the symbol sprayer
You can find many tutorials on the site for use with Illustrator such as the