labels

Hi, can anyone please tell me how to delete an image from address label using address book to make the labels?
I can figure how to create and change size etc of labels , but I clicked on set image (to see how it would look with an image) and now cannot remove the image. I can change the image for another but not delete.
I have looked (to no avail) all over the net trying to find the answer to this, I did find the same question asked on the macmost site but it wasn't answered.
Many thanks if someone knows the answer, but a word of warning don't click on set image just to see what happens or, like me, you will end up stuck with an image to the left of your address labels.
Peter

If anyone is plagued by the same problem, I have just figured a way around it.
Create a new document in a photo processing programme such as photoshop elements and resize the document to 1 pixcel X 1 pixcel then name the document 'label photo' and save it, then set image in label layout in address book to that image, the image is still there but not visible or large enough to be intrusive.
However , surely there should be a way of just being able to undo set image!
Peter