How do i place a button in the background?

I have quite a few labels and buttons on my view controller and I have an image and I have set it to the back in the layers part on the left. How ever when I make it bigger it seems to go to the front and block the images. I have tried multiple codes from other people who have the same problem, but it still doesn’t work. I am using Xcode 8, Swift, iOS.

In interface builder you can change the order of what is in front or behind by changing the order of the views as they appear in the Document Outline…

The higher up the list they appear, the further towards the back they are.