About displaying labels
Labeling is an easy way to add descriptive text to features on your map. Labels are dynamically placed, and label text strings are based on feature attributes. You can turn labels on or off by checking the box next to each layer and label class to label on the Label Manager.
You can use dynamic labeling for all features in a layer, or you can use label classes to specify different labeling properties for features within the same layer. For example, in a layer of cities, you might label those with a population greater than 100,000 with a larger font size and those with a population less than 100,000 with a smaller font size. In addition, if the features in your layer are symbolized with different symbols, you can create label classes from your symbology classes. Building your label classes from your symbol classes is a fast way to create maps with a consistent look.
The Labeling toolbar, Label Manager, and Label class summary dialog box
The Labeling toolbar is where you start labeling in ArcMap. From here, you can control the labeling process and open the Label Manager dialog box, which lets you view and change labeling properties for all the labels in your map. By clicking the Summary button on the Label Manager dialog box, you can access the Label class summary dialog box. This dialog box presents a general overview of the labeling classes in the data frame for quality assurance and performance checks.
General label settings
In addition to the parameters you can set to control the labeling of individual label classes, ArcGIS has global parameters you can use to control how labels are placed for all layers. These include the following:
- Setting the color of unplaced labels
- Controlling whether labels rotate with the data frame
- Setting the orientation of vertical labels
Because these are global parameters, you set them from the Labeling Options dialog box, which you can open from the Labeling menu.
Label symbols and styles
You control the appearance of dynamic labels by changing the label symbol. The label symbol is a text symbol that is used for all the labels in a layer or label class. Text symbols have basic properties, such as font, size, and color. You can also work with more advanced text symbol properties to add callouts, leader lines, shadows, halos, and other effects to your labels.
To change the appearance of your labels, you can either change the properties of the existing label symbol or choose a different text symbol from a style file. For instance, on a map of European capital cities, if you want to use a bold font, you can change the properties of the existing label symbol to make it bold. Or, since the ESRI style contains a number of text symbols that are useful for labeling, you can choose the Capital symbol from this style and use it to label the European capitals.
To reuse any text symbol for labeling, save that symbol to a style. Then you can use the saved text symbol for labeling, or any other purpose, in another map.
The following text symbol properties are not used when labeling:
- Angle—You can specify the orientation of your labels through the label placement properties.
- Vertical Alignment—The vertical alignment of labels is always bottom.
- Horizontal Alignment (Maplex Label Engine only)—You can specify the horizontal alignment of your labels through the placement properties.
Another option for changing the appearance of your labels is to choose a label style. A label style consists of both a text symbol and label placement options. You can change the appearance and positioning of labels by choosing a label style for your layer or label class. The ESRI style contains a number of useful label styles for labeling points, lines, and polygons; they are stored in the Labels style category. If you choose a label style, its text symbol replaces any text symbol currently set for your label symbol.
Changing X Offset and Y Offset for a text symbol is not recommended. The label engine first places the labels using the labeling parameters and symbol settings, then applies the offset values, potentially resulting in overlapping labels.
Showing unplaced labels
Often, there is not quite enough room to place the labels for all the features on your map. You can view the labels that were not placed by clicking the View Unplaced Labels button located on the Labeling toolbar.
Unplaced labels appear in red by default, although you can change the color of unplaced labels on the Labeling Options dialog box accessed from the Labeling menu of the Labeling toolbar.