Created: January 13, 2021 | Updated: January 14, 2021
This documentation page references Altium NEXUS/NEXUS Client (part of the deployed NEXUS solution), which has been discontinued. All your PCB design, data management and collaboration needs can now be delivered by Altium Designer (with Altium Designer Enterprise Subscription) and a connected Altium 365 Workspace. Check out the FAQs page for more information.

Parent page: PCB Commands

The following pre-packaged resources, derived from this base command, are available:

Applied Parameters: None


This command is used to add a new coverlay region.

A common feature on flex boards is the selective use of coverlay material. This insulation layer is cut and laminated onto specific areas of the board and because of this selective use, custom coverlay is often referred to as bikini coverlay. As well as its use in specific areas of the board, custom coverlay can also be positioned anywhere in the layer stack. 


The command is accessed from the PCB editor in Board Planning Mode by right-clicking over a Flex region then choosing Coverlay Actions » Add Coverlay. The required coverlay layer must be the active layer in the main design space.

The current viewing mode for the PCB document can be changed using the corresponding commands from the main View menu. To switch to Board Planning Mode, use the command of the same name, or use the 1 keyboard shortcut.


First, ensure that a coverlay layer has been added in the Layer Stack and is the active layer. After launching the command, a coverlay region will be added to the region.


  1. Coverlay is automatically added to cover the entire area of the board region on which it was added.
  2. Custom Coverlay is a mask layer and behaves as an additional Solder Mask layer. Solder Mask layers normally display and output as a negative, that is, the objects you see on the screen become holes in the fabricated mask layer. The on-screen presentation of Solder Mask can be configured to display as a positive if preferred (and, therefore, also the coverlay).
  3. In standard 2D display mode, the custom coverlay is shown as if it is on the top/bottom solder mask. This is simply a display feature. When output is generated, the top solder mask and the top custom coverlay are written out as separate data as are the bottom solder mask and bottom custom coverlay.
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