The patterns library contains an excellent selection of pre-defined patterns that you can apply to materials. You can edit patterns to suit your needs.
To customize the patterns library:
Select File > Catalogs > Catalog Manager, or right-click an element in the catalog panel and select Catalog Manager.
In the Catalog Manager, select Libraries > Patterns. The Patterns dialog appears.
Edit patterns as desired.
Click OK.
Note: You can also access the patterns library when editing the Patterned properties of a material, by clicking the pattern swatch in the Edit Materials dialog.