Mask features without masking the basemap in ArcGIS Online Map Viewer

Summary

Pixels used to draw each layer on the map in ArcGIS Online Map Viewer are blended to achieve a specific effect. Blend modes are able to mask features and default basemaps. However, masking default basemaps may not be desirable in some instances as shown in the image below.

This article describes how to mask features in ArcGIS Online Map Viewer using blend modes, without masking the basemap. In this example, a polygon feature layer is used to mask a point feature layer.

Procedure

1. In ArcGIS Online Map Viewer, open the web map and add the polygon and point feature layers to the map. Refer to ArcGIS Online: Add layers to maps (Map Viewer) for instructions.
2. In the Layers pane on the Contents (dark) toolbar, drag the polygon layer above the point layer.
3. On the Contents (dark) toolbar, click Basemap.
4. In the Basemap pane, click Current basemap and navigate to the Base section.
5. Click the Hide layer button to hide the basemap layers.
6. Navigate to the Layers pane on the Contents (dark) toolbar and add a new layer as a temporary basemap to the map. Refer to Step 1 for instructions.

Note: 
When adding the new basemap, click Add to map instead of Use as basemap. The new basemap is added to the Layers pane, instead of the Basemap pane. Ensure to position the new basemap layer to the top in the Layers pane.

7. In the Layers pane, click the basemap layer to display the Properties pane.
8. Navigate to Appearance, under Blending, click the drop-down arrow. Select Destination Over under Compositing.

9. Repeat Steps 7 to 8 for the polygon layer and select either the Destination In or Destination Out option under Compositing depending on the desired output. In this example, Destination In is selected.

10. On the Contents (dark) toolbar, click Save and open and click Save to save the map.

The image below shows the basemap is visible when masking point features with the polygon features.