Contrast in materials is shown using line shading on some surfaces and stippling shading on others.
Contrast in materials is shown using line shading on some surfaces and stippling shading on others.
| Number | Name | Date | Kind |
|---|---|---|---|
| D298448 | Seehaver | Nov 1988 | S |
| 5004256 | Won | Apr 1991 | A |
| 5330026 | Hsu | Jul 1994 | A |
| D413954 | Gerlach | Sep 1999 | S |
| D608851 | Hillman | Jan 2010 | S |
| D723123 | Norman | Feb 2015 | S |
| D724166 | Hamborg | Mar 2015 | S |