You can increase the number of labels placed in areas where there are label or feature conflicts by allowing the font size and width to be reduced using the Maplex Label Engine. You can reduce the font size from the labels' base font size to a minimum font size using steps of a given size. You can also reduce the length of a label by compressing it horizontally to a given percentage of its original length in discrete steps. These techniques can be applied together so the font width compression steps will be tried for each of the font size steps.
Reducing the font size
Reducing the font size reduces the overall size of labels in areas where there are conflicts. When you allow the Maplex Label Engine to reduce the font size, you can set a lower limit on the font size and define a step interval that instructs the font size variants for the label engine to try between the font's original size and the lower limit.
- Font Size Reduction Lower Limit is the smallest allowable reduced font size. This parameter instructs the Maplex Label Engine to reduce both the font height and width without changing the aspect ratio.
- Font Size Reduction Step Interval is the amount by which the font size may be progressively reduced to place a label.
For example, for a label with a base font size of 10 points, you might set a lower limit of 6 points and a step interval of 0.5. The Maplex Label Engine will try placing variants of the label using 10, 9.5, 9.0, or 8.5 points, starting at the base font size and reducing it by the step interval until the lower limit is reached. Once the label is placed, the smaller size levels are not tried. The maximum number of label font size variants that the label engine will try is 10.
The image below shows font size reduction being used to fit the Whispering Pines Lane label into the street feature. If font size reduction was not used, the label would not be placed on the map.
Compressing the font width
Compressing the width of the font for a label reduces the length of the label but not its height. As with font size reduction, you control how much the label is reduced by setting a minimum and a step interval. However, for font width compression, these limits are specified in terms of a percentage of the base font width of the label. The lower limit can range between 10 and 100 percent of the original font width, and the step interval can range between 1 and 50 percent of the base font width.
- Font Width Compression Lower Limit is the smallest allowable font compression ratio.
- Font Width Compression Step Interval is the amount by which the font width may be progressively compressed.
For example, you might allow the label engine to compress the width of the font in a label to 85 percent of its original width and use a step interval of 5 percent. The label engine would try to place the label at 100 percent of its original width. If it didn't fit, the label engine would try compressing to 95 percent, 90 percent, and 85 percent, stopping when the label fits. Once the label is placed at a certain compression level, the lower levels are not tried.
The image below shows font width compression being used to fit the Whispering Pines Lane label into the street feature. If font width compression was not used, the label would not be placed on the map.
Reducing and compressing labels
You can use font size reduction and font width compression together to increase the number of labels that will be placed. The Maplex Label Engine will try all the font compression levels for each font size before the font size is reduced by its step interval.
For example, if the base font size for a label is 10 points, and you set the lower font size limit to 8 points and a font size step interval of 0.5 points, there are five font size possibilities. If you also set the font compression lower limit to 85 percent and the compression step interval to 5 percent, there are four font compression levels. The Maplex Label Engine would try the resulting 20 size and width combinations in the following order:
- Font size of 10 pt, 100 percent font width
- Font size of 10 pt, 95 percent font width
- Font size of 10 pt, 90 percent font width
- Font size of 10 pt, 85 percent font width
- Font size of 9.5 pt, 100 percent font width
- Font size of 9.5 pt, 95 percent font width
- Font size of 9.5 pt, 90 percent font width
- Font size of 9.5 pt, 85 percent font width
- Font size of 8 pt, 100 percent font width
- Font size of 8 pt, 95 percent font width
- Font size of 8 pt, 90 percent font width
- Font size of 8 pt, 85 percent font width
- Enable the Maplex Label Engine.
- Click the Label Manager button on the Labeling toolbar.
- Check the check box next to the layer you want to label.
- Choose a label class under the layer.
- Click the Properties button.
- Click the Fitting Strategy tab.
- Check the Reduce font size check box.
- Click Options.
- Type a lower limit.
- Type a step interval.
- Type a lower limit.
- Type a step interval.
- Click OK to close all dialog boxes.
Although the steps are the same, some dialog boxes for line and polygon layers may differ.
The top section of the Label Reduction dialog box lets you control font size reduction. The label's base font size is listed for reference. The bottom section of the dialog box lets you control font width compression. The font height is not affected.
The font size of the labels is not reduced below this value.
The font is reduced from its current size to the lower limit in steps of this size.
The font is not compressed beyond this percentage of its current width.
The font width is compressed in steps of this size.