This tutorial will teach
you how to create a photo collage by cutting an object from one
image and placing it into another image.
Click here to open the source image
You will now place the object you created on the target image.
As long as the cactus remains an object, it floats above the image
background and can be moved independently. You can also add other
objects to your collage and place them as you wish.
When you are satisfied with your collage, click Object menu, Combine,
Combine All Objects With Background. The object is now a part
of the target image background, and can no longer be moved independently.
Click Mask menu, Invert.