Use built-in materials: If checked, FreeCAD's built-in materials will be listed.
Use materials from external workbenches: If checked, materials added by external (add-on) workbenches will be listed.
Use materials from Materials directory in user's FreeCAD preference directory: If checked, materials from the FreeCAD's preference directory will be listed.
Use materials from user defined directory: If checked, materials from the specified directory will be listed.
User directory: source for additional materials.
Card sorting and duplicates
Delete card duplicates: If checked, duplicate material are deleted from the list.
Sort by resources: If checked, material are shown sorted by their resources (locations). If unchecked, they are sorted by their names.
Material Selector
Show favorites: If checked, materials added to Favorites are shown in the Material Selector.
Show recent: If checked, recently used materials are shown in the Material Selector.
Show empty libraries: If checked, empty libraries are shown in the Material Selector.
Show empty folders: If checked, empty folders are shown in the Material Selector.
Show legacy files: If checked, legacy files are shown in the Material Selector.
Material Editor
Show favorites: If checked, materials added to Favorites are shown in the Material Editor.
Show recent: If checked, recently used materials are shown in the Material Editor.
Show empty libraries: If checked, empty libraries are shown in the Material Editor.
Show empty folders: If checked, empty folders are shown in the Material Editor.
Show legacy files: If checked, legacy files are shown in the Material Editor.
Default Material
Default Material preferences
Default Material
Material Selector: Specifies the material used by default in FreeCAD.