My boolean/difference operation didn't work I'm relatively new to Blender and I'm trying to apply the Boolean modifier to substract channels from the water bottle holder.



I added the  the Boolean modifier to the Cylinder, with Difference as the operation, and the target object as the Plane... But when I removed the plane it had not affected the cylinder.

So I read some advices from similar cases on Stackexchange (flip faces), but the boolean still does not work for me.
The modifiers are designed so you can change them later; if you changed the target object, it would change the effect. Similarly, if you delete the target object, it will remove the effect!

What you need to do is to apply the modifier. There should be an Apply button just beneath the 'add modifier' popup.

Note that this will make it impossible to remove the effect again later (except manually, of course), but if you're deleting the plane anyway, it should be what you need.