Press the Edit button on the right-hand side of the panel. The Global Edit dialog will now appear.
Uncheck the 'Visible
in list' box and select OK.

Turn off all the filters in the filter dialog or ensure that the Use Filters box on the main panel is NOT pressed.
The Pathtrace example data will no longer be displayed in the Materials list.
Two sets of Pathtrace example materials are now invisible. On the next page you will be shown how to retrieve invisible materials.