Reducing the size of the label text

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. 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 ESRI 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.

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 ESRI 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.

Line labels set with the font size reduction parameter

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.

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.

Line labels set with the font width compression parameter

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 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 ESRI Maplex Label Engine would try the resulting 20 size and width combinations in the following order:

Steps:
  1. Click the Label Manager button Label Manager on the Labeling toolbar.
  2. Check the check box next to the layer you want to label.
  3. Choose a label class under the layer.
  4. Although the steps are the same, some dialog boxes for line and polygon layers may differ.

  5. Click the Properties button.
  6. Click the Fitting Strategy tab.
  7. Check the Reduce font size check box.
  8. Click Limits.
  9. 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.

  10. Type a lower limit.
  11. The font size of the labels is not reduced below this value.

  12. Type a step interval.
  13. The font is reduced from its current size to the lower limit in steps of this size.

  14. Type a lower limit.
  15. The font is not compressed beyond this percentage of its current width.

  16. Type a step interval.
  17. The font width is compressed in steps of this size.

  18. Click OK to close all dialog boxes.
TipTip:
You can also open the Placement Properties dialog box by clicking the Placement Properties button on the Labels tab of the Layer Properties dialog box for the layer that you want to label.
TipTip:
The font size and width will not be reduced if the label expression contains text formatting tags that specify the label's font size and type.
TipTip:
Be aware of the proportion of the initial font size, lower limit, and step interval values. More trial sizes mean more processing time.

Related Topics


5/2/2011