Some labeling situations can create crowded areas where labels are placed close to each other. This can decrease the readability of a map, especially when it becomes unclear which features are being labeled. The Maplex Label Engine Label buffer parameter allows you to improve the clarity of such maps by specifying a buffer distance around each label in which no other labels are placed. By increasing the buffer size, a larger amount of white space is created around labels, making it easier to distinguish one label from another.
When a label buffer is specified, the Maplex Label Engine uses this buffer as a guide for the trial positions and places the labels with their buffer if there is space available. The placement of the label may not be in the first trial positions to accommodate the buffer. If creating a buffer for a label would result in unplaced labels, the label engine does not create the buffer, resulting in closely placed labels. In this situation, no labels are dropped from placement.
If the Hard constraint option is used, the buffer is respected regardless of available space. This results in well-spaced labels but also in the possibility of many unplaced labels.
If you are using label offsets, you should set the label buffer to be slightly larger than the preferred label offset. This helps avoid ambiguity on the map.
- Ensure that the Maplex Label Engine is enabled.
- Ensure that List By Labeling is the active method of displaying the Contents pane. Click the List By Labeling tab .
- Choose a label class in the Contents pane and click the Labeling tab.
- On the Labeling tab, in the Label Placement group, click Label Placement Properties .
- In the Labeling pane, click Position and click the Conflict resolution tab .
- Expand Buffer.
- Specify a Label buffer value as a percentage of the font height. The default is 15 percent, and the maximum is 50 percent.
Very large label buffers restrict the amount of available space for placing labels and may result in fewer labels being placed.
- Optionally, check the Hard constraint check box.