Render to a texture. > Material Editor > Pick Material from Object > Click object with “baked” material.
The Shell material is for use with texture baking. When you use Render To Texture to bake a texture, it creates a Shell material that contains two materials: the original material used in the rendering, and the baked material. The baked material is a bitmap that is saved to disk by Render To Texture. It is “baked,” or attached to an object in the scene.
The Shell material is a container for other materials, like Multi/Sub-Object. It also lets you control which material is used in which renderings.
Note: The Material/Map Browser lists the Shell material when you assign a new material. You can apply two materials to a single object this way, but changing a material's type to Shell does not generate a baked texture that is saved to disk.
Original Material—Displays the name of the original material. Click the button to view that material and adjust its settings.
Baked Material—Displays the name of the baked material. Click the button to view that material and adjust its settings.
In addition to the color and mapping of the original material, the baked material can include shadows from lighting, and other information. Also, a baked material has a fixed resolution.
Viewport—Use these buttons to choose which material appears in shaded viewports: the original material (upper button) or the baked material (lower button).
Render—Use these buttons to choose which material appears in renderings: the original material (upper button) or the baked material (lower button).