This post will cover the last six functions in the Pathfinder tool: Divide, Trim, Merge, Crop, Outline, and Minus Back.
Divide: Takes all the lines in the picture and creates a shape wherever the lines form a closed path. Here’s an example. The starting shapes are one circle and two squares, and the final image on the right shows the resulting shapes pulled away from each other:
Divide will also work with strokes, not just with closed paths:
If an open path has a fill, Divide will treat the edge of the fill like a line:
Trim: What you see is what you get. Does not work on paths that have no fill.
Merge: Like Trim, but unites all shapes with the same fill afterwards.
If a solid shape is “cut” by another shape of a different color, it will be split into pieces.
Crop: Uses the top shape as a window to crop any shapes beneath it.
Outline: Replaces the stroke color with the fill color. Removes the fill. Breaks the stroke of each shape into different segments based on where they intersect.
Note that the bottom right corner of the orange square, which is hidden behind the blue circle, ends up colored blue:
Minus Back: Takes the top shape, and subtracts the area of any lower shapes. If there are more than two shapes selected, all of the back shapes will be subtracted from the single front shape.