The background-clip property specifies the painting area of the background image or background color.
The default value is:
This means that the background is clipped to the border box, i.e. the background is visible under the element’s border.
Other values for background clipping:
padding-box – clips the background at the outside edge of the element’s
padding, i.e. the background is not visible under the element’s border
content-box – clips the background at the edge of the content box, i.e. does
not apply the padding or border
If you are still not sure how to use the
values, take a look at the box-sizing property example.
See a live example at cdpn.io/e/yamFI.
Let’s put it simply: IE9+. Polyfills for IE8 do not even exists and no wonder - it’s hard to find a situation where they would be necessary.