How do I use ModelBuilder in ArcMap


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In ArcMap, variable depth masking is a display method for hiding parts of layers that are drawn below symbols and annotation. This topic describes how to use polygons to mask overlaying symbols and how to make maps more readable and easier to use.

Masking is used to make maps that have a high density of annotation and symbology clearer. You can use a polygon masking layer to mask certain aspects of a layer and add map text and other symbols on top. The aim here is to make the map easier to read.

For example, many of the labeled polygons on the map below contain a pattern. Using a mask to remove the patterns around the annotation features makes the map easier to read and use.

In the contour map example below, contour lines and annotation features overlap. However, if you apply masking to the annotation, the areas of the contour lines are hidden, while the elevation shading behind these layers remains visible.

Create a masking layer

You can use any polygon feature class as a masking layer. Typically, special masks should be created using the symbology or annotation of a particular layer.

Several geoprocessing tools are used to create masks. This includes:

Dead-end masking

Masking for feature outlines

Masking for intersecting layers

The Feature Outline Mask tool works for a layer in the current map document in ArcMap or for any layer (.lyr) file. A polygon feature class is generated as output in a geodatabase. These mask polygons are then used to mask portions of layers that underlie certain symbols or annotation features.

To create the mask, we first identify an edge (the area between the feature and the edge of the mask) and use an outline method. The following outline methods are available:

  • Exact - The mask is created exactly as the shape, including any holes it contains, and for text components, the text is masked exactly.
  • Convex Hull - The mask is created exactly like the shape, and any holes it contains are not taken into account. There are z. B. Words masked and not every single letter in the word.
  • Box - The mask frames the shape as a rectangle.


  1. Click the ArcToolbox Window button on the main menuto open the ArcToolbox window.

  2. In the Cartography Tools toolbox, navigate to the Masking toolset.

  3. Double-click the Feature Outline Mask tool to open it. Then set and run the parameters to create a polygon feature class for masking.

Use a masking layer

You can use any polygon feature class as a masking layer. The previous section describes one way you can create a feature class that can be used as a masking layer.

When applying masking, a masking layer can be specified for one or more layers.


  1. First, add the masking feature class to the map's table of contents as a layer.
  2. Right-click the data frame name in the table of contents and open the Advanced Display Options dialog box.
  3. Select the Display with masking options below check box. Uncheck this box to disable masking.
  4. In the Masking Layers list, click the layers that you want to use as masking.
  5. In the Masked Layers list, select all layers that you want masking to affect.
  6. Click OK.

You can exclude individual symbol layers of a symbol from masking by using the Allow layers to be linked to masked layers option in this dialog box. This option allows more detailed control over mask linking.

Printing and exporting maps with masking

Note that adding masks to cards can affect card creation, card printing, and export performance. In general, there are three things to keep in mind when creating masks for maps:

  1. Number of masks
  2. Complexity of the masks
  3. Use masks to mask polygon features that are filled with marker or line symbols

If the number or complexity of the masks increases and marker symbols or polygon hatches are masked, this can increase the time it takes for the map to be displayed. It can also happen that no valid output is generated when printing and exporting. This is because there are restrictions on how graphics file formats save the results of exporting maps that contain masks.

If you want to improve the display performance and the performance and reliability of printing and export processes, the most important basic rule is: Simplify the masking and use it sparingly.

When masking annotations, masks of the type CONVEX_HULL are usually sufficient. If you need more detailed text masks, use the EXACT_SIMPLIFIED mask type.

In general, when masking large amounts of text on relatively large cards, you should avoid using the EXACT mask type, as too many complicated maskings are created.

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