You can remove a raster line by picking a point on each end of the raster line. You must set an appropriate line width. For more information, see Rub and Crop Line Width.
Note: Unlike previous versions of AutoCAD Raster Design toolset, rubs permanently change the raster data after you have saved the image. They do not temporarily remove raster data from the display. To reverse a rub, use the AutoCAD UNDO command.