Use this procedure to mask a column grid. A mask is a polyline shape that defines the boundaries of a column grid. Those parts of the grid outside the boundary are not displayed.
- Draw a closed polyline with the boundary or hole shape you want.
- Select the grid you want to mask.
- Click
. 
- Select the column grid, and press Enter.
- Select the closed polyline you want to use as a mask.
The parts of the column grid that are outside the masking polyline are no longer displayed.
Tip: If columns are connected to the invisible part of the grid, they are still displayed after masking. If necessary, you can delete them.
Tip: If you want to restore the original grid shape, go to the Properties palette, and select None for Boundary.