1. Click File > Prepare > Model Properties. The Model Properties dialog box opens.

2. Click change against Material. The Materials dialog box opens.

3. Click File > New. The Material Definition dialog box opens.

4. Type a name for the material in the Name box.

5. Type a description for the material in the Description box.

6. In the Density box, type a value for the density of the material and select the unit of measurement from the adjacent list.

7. Define the properties of the material using the tabs below the Density box.

8. To save the material to the library, follow these steps:

a. Click SaveTo Library. The Save a Copy dialog box opens.

b. Browse to the library folder and click OK. If you have added or edited appearances then the Save dialog box opens.

c. Click OK. By default, the appearances are saved in a file named global.dmt.

9. To save a material to the model, click Save To Model. The material is saved to the model and appears in the Materials dialog box in the Materials in Model column.

10. To copy an existing material in a model, select the material to copy in the Materials in Model list, and click Edit > Copy in the Materials dialog box. The copy appears in the Materials in Model list as Copy_of_<name> while subsequent copies of the same material appear as Copy1_of_<name>, Copy2_of_<name>, and so on.

11. Click OK in the Materials dialog box.