# Define a Mask for a Downstream Tool

When Cognex ViDi Tools are connected together in a tool chain, a mask that was created for a preceding tool will be used by the following tool(s). In this scenario, if a mask was created in Tool 1, and Tool 2 is chained to Tool 1, Tool 2 will inherit the mask of Tool 1. If you add an additional mask to Tool 2, while editing Tool 2, then Tool 2 will use both masks.

To edit the mask of Tool 1 for use by Tool 2, you have to select Edit Mask while Tool 1 is the active tool.