Use Layer preferences to define the default settings for new layers. Choose Edit > Preferences and then click Layers to change Layer preferences.
Tag Determines the default tag used to define the layer. SPAN and DIV create CSS layers; LAYER and ILAYER create Netscape layers.
Visibility Determines whether layers are visible by default.
Width and Height Set the default width and height of layers created by Insert > Layer.
Background Color Determines the default background color.
Background Image Specifies a default background image.
Nesting Makes a layer drawn within the boundaries of an existing layer a nested layer. Press Control (Windows) or Command (Macintosh) to change this setting temporarily while drawing a layer.