2008

The cylinders are subtracted to form holes in the box.
You only have to perform Boolean operations once instead of several times.
This method is far more efficient and less prone to errors. It is also very useful
for cutting rough openings for doors and windows into a wall if you're already
working with 3D geometry. Next, you'll find an example for working with 2D
spline objects.
Splines and Boolean Operations
Performing Boolean operations on splines made from the Create panel >
Shapes menu can be confusing. 2D spline shapes do not use the Boolean
operation you'd use for 3D geometry. Shapes, converted to Editable Splines,
offer Boolean functionality from the Modify panel > Geometry rollout. Unlike
Boolean operations performed on two separate pieces of 3D geometry, Boolean
operations can only be performed on single splines.
Therefore, one of two things must be done before you can perform Boolean
operations to spline shapes.
■ When originally creating the shapes, make sure Start New Shape is turned
off on the Create panel > Shapes > Object Type rollout. When turned off,
Fixing Boolean Problems | 7671