By default, line fill symbols in ArcMap do not contain a background, so the background would apprear to be transparent. A colored background should be assigned to the symbol.
These steps are for adding a background and assigning a color for a line fill symbol.
- Open the Symbol Selector dialog by double-clicking the desired layer patch in the ArcMap table of contents.
- Select a line fill pattern.
- Click Properties to open the Symbol Property Editor.
- Add a new empty symbol layer by clicking the plus button located beneath the symbol Layers section.
- Click the Type dropdown and set it to Simple Fill Symbol.
- With this new simple fill symbol layer active, change the color to the desired background color, and can also change outline color, style, or width.
- Move the newly created background fill to the bottom of the drawing order by clicking the down arrow button until it appears at the bottom of the list.
The upper most layer symbol will draw last or on top of the lower layers.
- Click OK through the various open dialog boxes to return to the map display.