Brushstrokes are not maintaining their width when being cut? (Automatically Readjusting)

[Rolando Riggio]

I would like to cut off the section of the brush strokes that go past the bottom of the mushroom stem but I am running into the unwanted action of my brush strokes resizing when I try to cut them off with the Shape Builder tool:

[Doug A Roberts · Accepted solution]

The brush will change depending on the length of the path it is applied to. If you want to cut them as they are, your options are a clipping mask, or expand them and adjust the resulting shape.