Strange behavior of Minus Front in Isolation mode of compound shape

Question

So I have the shapes above (2 circles and 2 rectangles as seen in layers panel) I selected all and made a compound shape with alt+click on Exclude (I also tried tried the same with Unite and got the same odd behavior).

Then enter Isolation mode to edit them I select 2 shapes there to apply Minus front.

The thing is Minus front is not acting properly. it seems to just remove both selected shapes instead of just removing the top. (I tried reordering both shapes and I get the same results still).

If it helps below is the result I expect and I get if I do Minus front right before the creation of the compound shape.

Any help in explaining why this happens is appreciated (PS. the reason is that I'm trying to understand the behavior rather than just edit them).

Answer 1

Don't "alt-click", just click.

• When you hold down the Option/Alt key and click a button on the Pathfinder Panel what you get is a live shape, with the ability to move around the individual pieces of the combined appearance. Essentially you get a dynamic clipping mask that is set up to resemble what the expanded artwork would look like. None of the objects/shapes are actually altered until you expand the artwork.

• Without the Option/Alt key, the Pathfinder panel automatically expands the multiple shapes into a combined shape (or shapes based on the specific pathfinder operation).

(Note: for Illustrator CS4 or earlier, the above explanations are reversed)

So what is most likely happening is you are "alt-clicking" Exclude, which leaves 2 live shapes. Then when you click Minus Front the frontmost shape is used, but pathfinder is seeing both parts of your exclude operation as individual pieces, not a single combined shape.

If you want to retain the live shapes, that may be possible, but you'll have to rethink and most probably use clipping masks as opposed to Pathfinder operations.

Answer 2

Assuming your expected result is actually the goal then your first step of making a compound shape of the whole things is completely unnecessary and the wrong thing to do; because 1. you have multiple colors, and 2. you want to use pathfinder separately on the 2 shapes^*. A compound shape, for all intents and purposes is a single shape, so you can't do either of those things.

What you really want is 2 compound shapes (or just use pathfinder without creating compound shapes and create two shapes), then you probably just want to group them rather than creating a compound shape.

^* You kind of can (and this actually explains your strange behaviour)....

Each individual component in a compound shape can have its own shape mode, but these modes are a property of the component, not an operation you apply to a number of components... So when you are inside a compound shape you don't select two components and hit the shape mode, you change each shape's mode individually (which means the Pathfinder shape mode buttons do an inherently different thing when you are inside a compound shape)...

Compound shapes and Pathfinder are explained more here:

• How to combine objects in Illustrator - Adobe Support