The cell’s interior background style.
- macOS 10.5+
The interior background style describes the surface drawn onto in the
draw method. This is often the same as the
background, but a button that draws a bezel would use a different value for this property.
In a custom button with a custom bezel you can override this property and return a different value to describe that surface. A cell that has custom interior drawing might use the value of this property to pick an image that looks good on the cell.