Bootable USB created by Balene Etcher won't boot Macbook but Rufus works

I need to use Clonezilla (Dec 2019) to create a clone image of my Macbook and write a different image to it. The Macbook is late 2006, and is white. It is NOT a Macbook Pro.
I am using my Windows 7 computer to create the bootable USB stick that holds the live version of Clonezilla .
If I create the bootable live Clonezilla USB using Balena Etcher, my Macbook cannot see it and cannot boot from it, but if I create the bootable Clonezilla USB stick using Rufus, my Macbook can see it and and will run it.
And the same problem happens if I try to create a bootable USB stick for GParted.
Why can’t Etcher create a bootable USB stick for my Macbook, but Rufus can?

Hi Michael
Rufus is software designed to create bootable USB drives. In contrast Etcher copies images to drives - it will not modify the mage that you are trying to write to a USB stick. It only copies it.
If your image is not capable of booting in a certain environment etcher will not change that. Rufus in contrast is able to add certain requirements to an image to make it boot in a target environment.
Cheers Thomas