Watch this video in context on the official Unity learn pages -
http://www.unity3d.com/learn/tutorial...
In this live training session we will learn a workflow for laying out a simple 2D scene using 2D sorting groups, sprite meshes and 9-Slice sprites introduced in Unity 5.6. We will use these tools to create a simple 2D game. In this episode we will look at Sorting Layers and 9-Slice Sprites.