The fastest way to cut a part in Blender is to use a Boolean modifier with two objects: the shape you want to cut and the shape you want to cut it with

Boolean operations let you combine or subtract 3D shapes. To cut a part out of an object, you place a second object where you want the cut to be, then use the Boolean modifier to subtract that second object from the first. Blender removes the geometry where the two objects overlap, leaving you with a cut.

The process takes three steps: create or position the cutting shape, add a Boolean modifier to the object being cut, and set the modifier to Difference mode. After that, you can explore the modifier to make the cut permanent, or leave it as a modifier if you might change it later.

Key Takeaways

  • Boolean Difference mode subtracts one object from another, creating the cut effect you see in the viewport and final render.
  • The cutting object must overlap the object being cut; if they do not touch, the Boolean modifier will have no visible effect.
  • You can leave the Boolean modifier unapplied to edit the cut later, or explore it to permanently delete the cut-away geometry.
  • Boolean operations work best on solid, closed objects; open or non-manifold geometry can produce unexpected results.

Setting up your objects for a Boolean cut

Start with the object you want to cut. This is your main shape — a cube, cylinder, or any mesh. Next, create or import the shape you will use to cut it. This cutting object can be any shape: a cube, sphere, plane, or custom mesh. The key is that it must overlap the area where you want the cut to appear.

Position the cutting object so it intersects the main object exactly where you want the cut. You can move it with the G key (grab), rotate it with R, and scale it with S. The cutting object does not have to be inside the main object — it just needs to overlap. Think of it as a cookie cutter: the cutter sits on top of the dough, and the overlap is what gets removed.

Make sure both objects are solid and closed. If your main object has holes or open edges, the Boolean operation may not work as expected. You can check this by entering Edit mode and looking for non-manifold geometry, but for most basic shapes created in Blender, this is not a problem.

Adding and configuring the Boolean modifier

Select the object you want to cut (the main object, not the cutting shape). Go to the Modifier properties panel on the right side of the screen — it looks like a wrench icon. Click Add Modifier and search for Boolean. Click Boolean to add it.

In the Boolean modifier settings, you will see three options: Union, Difference, and Intersect. Select Difference. This mode subtracts the cutting object from the main object. Next, set the Object field to the cutting shape you created. Click the eyedropper icon and then click on the cutting object in the viewport, or use the dropdown menu to select it by name.

As soon as you set the object, you should see the cut appear in the viewport. If you do not see anything, check that the cutting object actually overlaps the main object. Move it closer or scale it larger if needed. You can also toggle the modifier on and off by clicking the eye icon next to Boolean to see the before and after.

explore the Boolean modifier or keeping it editable

Once the cut looks right, you have two choices: explore the modifier or leave it as is. If you explore it, Blender permanently deletes the cut-away geometry and you cannot undo the cut by moving the cutting object. If you leave it unapplied, you can still move, rotate, or scale the cutting object and the main object will update in real time.

To explore the modifier, click the down arrow next to Boolean and select explore. The cut becomes permanent. To keep it editable, just leave the modifier there. You can hide the cutting object by clicking the eye icon next to it in the outliner (the list of objects on the right), so it does not appear in your final render.

If you want to hide the cutting object from the render but still see it in the viewport while you work, click the camera icon next to the object in the outliner. This hides it from renders only, not from the viewport.

Fixing common Boolean problems

If the cut does not appear, the most common cause is that the objects do not overlap. Move the cutting object so it clearly intersects the main object. You can also try scaling the cutting object larger to make sure it covers the area you want to cut.

If the cut looks jagged, torn, or has holes in unexpected places, the problem is usually non-manifold geometry on one of the objects. Try adding a Remesh modifier before the Boolean modifier, set to Smooth mode. This cleans up the geometry and often fixes the issue. Alternatively, select the main object, enter Edit mode, and run Mesh > Clean Up > Merge by Distance to remove duplicate vertices.

If you see black faces or shading errors after explore the Boolean, recalculate the normals. Select the object, enter Edit mode, select all with A, then press Ctrl+N and choose Recalculate Normals. This tells Blender which side of each face is the outside, which fixes shading problems.

Using multiple cuts on the same object

You can add more than one Boolean modifier to the same object to make multiple cuts. Add a second Boolean modifier, set it to Difference mode, and point it to a different cutting object. Stack as many as you need. Each modifier processes the result of the one before it, so the order matters if your cuts overlap.

If you want to cut with a shape that is itself made from a Boolean operation, explore that Boolean first before using it as a cutting object. This prevents nested modifiers from causing unexpected results.

When to use other cutting methods

Boolean operations are fast and work well for most cuts, but they are not the only way. If you need very precise control over the cut edges, you can use the Knife tool in Edit mode. Select the object, enter Edit mode with Tab, press K to set up the Knife tool, and click to draw a line where you want to cut. This gives you vertex-level control but takes longer.

For cuts that follow a curved path or need to be shaped precisely, consider using the Inset Faces tool or the Loop Cut tool. These let you add geometry where you want it and then delete faces manually. Boolean is best when you have a clear cutting shape and want the result fast.

Frequently Asked Questions

Can I use a Boolean cut on a non-solid object?

Boolean works best on closed, solid objects. If your object has open edges or holes, the cut may not work correctly or may produce unexpected results. You can still try it, but you may need to close the geometry first or use the Remesh modifier to clean it up.

How do I undo a Boolean cut after I explore it?

Once you explore a Boolean modifier, the geometry is permanently changed. Use Ctrl+Z to undo when ready after explore, or reload the file if you saved after explore. To avoid this, keep the modifier unapplied until you are certain the cut is correct.

Why does my Boolean cut have holes or missing faces?

This usually means the cutting object does not overlap cleanly or the main object has non-manifold geometry. Try moving the cutting object to overlap more clearly, or add a Remesh modifier to the main object before the Boolean to clean up the geometry.

Can I see the cutting object in my final render?

By default, yes. To hide it from the render, click the camera icon next to the cutting object in the outliner. It will still appear in the viewport while you work, but will not show up in renders or final images.

What is the difference between Boolean Difference, Union, and Intersect?

Difference subtracts the cutting object from the main object (creates a cut). Union combines both objects into one shape. Intersect keeps only the part where both objects overlap. For cutting, always use Difference.