- In Workshop, from the Tools menu, select Setup.
- In the left pane, click the arrow next to Material, to expand the Material section.
- Click Substrate.
A list of the available substrates is displayed in the center pane.
- In the center pane, select the name of the substrate.
- On the Sizes tab, select the size that you want to delete, and click the Delete button.
- On the toolbar, click .