Everything Enabling Overlay and Underlay Art Layers T-LAY-002-004 By default, the Overlay and Underlay art layers are disabled to simplyify the workflow. You can enable the support of those additional art layers in the Preferences panel. How to enable the Support Overlay and Underlay Arts option Select Edit > Preferences ( Windows/Linux ) or Harmony Advanced > Preferences ( macOS ). In the Preferences dialog box, select the Advanced tab. In the Advanced Options section, select the Support Overlay and Underlay Arts option. Click OK.