A number of useful Materials Browser-related commands are accessible using context menus. Context-click on any material's icon or name to access the Materials Browser's context menus. The following options appear depending on whether you are clicking on icons in an established materials collections or in the In Model materials.
Use the Remove menu item to remove a material from the In Model materials.
Use the Edit menu item to place the current material in the Edit Panel.
Use the Duplicate menu item to duplicate the material. The Color name dialog box appears. Enter a new name for the duplicated material in the Color Name field. Click OK.
Additionally you have the option to create and edit Material libraries using the "List" menu below the material thumbnail pane.
Use to create a new Materials library. Enter a new name for the Material library in the List Name field. Click OK.
Create a new library which contains all of the materials currently available in the selected library. A List Name field appears, enter the desired name and click OK.
If you have a library selected you can remove the entire library from the Materials browser.
Use the Purge Unused menu item to remove all materials in the In Model materials that are not actually used in your model.
Use the Delete All button to delete all materials in the In Model view, whether they're in use or not.