I can say for certainty, that many people who use Illustrator have some confusion over all the Align/Distribute icons in the AI control bar. "They all look the same" is the most common comment I hear. Then what is this Align to... drop down and what does it really mean. Using the Distribute section of the Align, it seems to not distribute things with equal spacing... or it does sometimes but not others. Here is the definitive guide on how to use and UNDERSTAND all the ins and outs of the Align/Distribute options. They can be very useful... once you know how they really work!
To begin with the Align Options, you have to have at least 2 objects selected in order for the Align/Distribute functions to show in the Control Bar. You can always open the Align/Distribute Panel under the Window Menu>Align.
(Or, if you have 1 object selected AND the Align to Artboard option selected, then these option will show up... but that is explained a few lines later...)
With 2 or more object selected, you can align the Right edges, Left edges, Top edges and so on. Simple.
When you have multiple objects selected and you choose an alignment options, ALL of the selected objects will align. ALL of them!
In this case, I chose Align left, so ALL of the objects aligned left. Illustrator does not pay attention to the edge of EACH column, just the absolute edge/center OF EACH OBJECT. Thus, ALL get aligned to the left.
When choosing the Align functions, how does Illustrator know WHICH OBJECT to align things to? Well, if the TOP align is chosen, it picks the top most object. Left align, the left most object, Bottom align, the bottom most object. In the Align Panel this is called Align To Selection.
How can you change which object it will align to otherwise? Easily, by using the Align to Key Object.
Once you select your objects, click on the Object you wish to align all the other objects too. This will be indicated by the thicker blue outline on the object. That is now your Key Object.
You will see in the Align Panel that the lower right icon now shows up as a key, indicating alignment on the object you selected. But wait... you can't see that because Illustrator doesn't show all the options in the Align Panel by default!!!
You have to click on the "Cheese Grater" on the Align panel to get the Show Options to see all the rest of the Align panel. This still annoys me that it doesn't show by default.
However, those options do show up in the Control Bar as well.
Now with your Key Object selected, all the objects will align to THAT Key Object once you click on how you want them aligned.
You can also Align to the Artboard if you want to position a single shape or multiple shapes to the center, left right, top, bottom of the art board.
3 objects selected, aligned to the center (vertically) on the Artboard.
To use the DISTRIBUTE FEATURES, you need to have 3 or more object selected. (Or just 2 if you use the Distribute to Artboard... again, getting ahead here...)
To many, this means it will space the object out equally. YES and NO!! This will space out the object equally from the CENTER, LEFT, RIGHT (depending on which align you choose). It looks fine when you use object that are the same size. So YES!
Objects of different sizes, NO it does not look right.
The Distribute works by setting the first object and the last object in the position you want them ( I call this "fence posting"). All the other object fall in between and get distributed in between the 2 ends.
If the object are different size, when I choose the Distribute (in this case, vertically align the CENTERS), I end up with spacing that is not the same in between the objects.
Here is the vertically distributed objects that are equally spaced apart when measure from their CENTERS.
Yes the spacing is off, but the space between the centers is EXACTLY the same.
So you want the spacing BETWEEN the objects to be the same, even when the objects are different sizes! So you need to choose the Distribute Spacing options at the bottom of the Align Panel.
Select 3 or more objects, then use the Distribute Spacing between the object, either horizontal or vertical. Then the SPACING will be the same BETWEEN, regardless of the size of the objects.
But I want to give it an amount of spacing between, not just have it balanced between my first and last object. I can't, the box is not active!!!
The "key" to this is you must have all your objects selected AND choose from the Align To options: Key Object. Then and only then will the spacing option come to life. Set the actual measurement in between AND press the Distribute Spacing options you want (vertically or horizontally).
Many times people will enter the value and nothing happens... you MUST press which spacing option you want after you enter the value.
You can also Distribute the spacing between 2 or more objects between the edges of the Artboard as well.
Select 2 or more objects, choose Align to Artboard in the Align to options, the click on the Distribute Spacing option you want.
Note: it put the object EDGE on the edge of the artboard, these objects have strokes that are aligned to the middle of the object so half the stroke is inside and half outside the object, giving the appearance that the objects are not really at the edge of the artboard.