The Blackboard defines the Properties that will be exposed to materials using the shader. Here you can define a range of Property types as well as their various names, attributes and default values.

You can also rename the Shader Graph Asset and change its path in the shader dropdown list by selecting their fields in the Blackboard's title bar. When editing a Sub-graph the path field will set the Sub-graph's path in the Create Node Menu.

The Blackboard can be moved to anywhere in the Shader Graph Window and will automatically move with the nearest corner of that window.

To create a new Property, click the Add button on the Blackboard title bar and select the Property type.

Properties on the Blackboard can be reordered by dragging them in the list. They can be deleted with Delete (Windows) or Command + Backpace (OSX). You can rename a Property by double clicking on its entry. Instances of a Property can be created in the shader by dragging them on to the Graph.

For a full list of Property types see Property Types.