Subtract a path from a shape in Illustrator CC 2015

Question

The pathfinder shape subtracts shapes from shapes fine e.g. the berry ellipse from the blue rectangle:

But it doesn't subtract paths from shapes at all, e.g. the purple line from the blue rectangle (NOTE: Before performing the subtraction I did move the line in front of the rectangle by using Arrange > Bring to Front, so that's not the issue):

The result is that nothing happens. I really want to trace a path and subtract it from the shape. I could set the stroke color to the background color, but when I save this as an .svg, I want the area to be transparent. Do I need to convert the path into a shape? The shape into a path? I'm new to illustrator so I'm really lost at the moment. Any help/suggestions are appreciated!

Answer 1

Pathfinder shape modes don't work well with open paths and completely ignore strokes. Since the actual path you're trying to subtract has 0 width, there is nothing for it to subtract.

If you want to subtract the purple stroke you need to outline the stroke first. Simply select the stroked path and go to Object → Path → Outline Stroke. That will turn your stroke in to an actual shape that will work with pathfinder the way you want it to.

Answer 2

So you have something like this right?

And you want something like this

In case you do, well this is the solution.

If you want to subtract something make sure the paths that you have are expanded because Illustrator don't extract open paths. So, selecting the path go to Object > Expand > ("Fill" and "stroke" should be marked) Ok Once you path is expanded you can subtract it from the shape.

I wish I answer the question

Good luck!

*I'm using Adobe Illustrator CC