Default Layers is a list of Layers automatically added to new Bids. Layers with a check-mark in the Show column in the Default Layers dialog box are set to Show when added to new Bids (Layers can always be toggled on/off within the Bid). For more information about using Layers to manage what is displayed on the Image Window, see About Layers.
The Default Layers dialog and the Bid Layers dialog, accessed from the Image Tab, are two separate lists. The Layers dialog box is unique to the current Bid while the Default Layers dialog lists the Layers that are automatically added to new Bids.
Don't mistake "Default Layers" with the Default LAYER that is added to every Bid (always highlighted in blue in the Layers window). The Default LAYER is where all takeoff created with Conditions not assigned to a specific Layer is stored. (the "Default" layer is a Default Layer...)
To add a Default Layer:
The Image, Annotation, and Default Layers (highlighted in blue in the list) are permanent System Layers and cannot be deleted from the Default Layers dialog (or any Bid). The Layer named "Default" IS a Default Layer and is added to every Bid.
The Image Layer contains the actual electronic plans
The Annotation Layer contains annotations such as Hot Links, Text, Dimension Lines, and the Image Legend
The Default Layer contains all takeoff for Conditions not assigned to a specific Layer
When a Layer is added to the Default Layers dialog list, it appears in the Bid Layers dialog for every new Bid created after it is added to the Default Layers list, it will NOT automatically update the Layers List for previously created Bids.