Technical data

62 Using Layers and Masks
Suppose you are creating a new picture image. The New Image dialog
provides three choices for Background: White, Background Color,
and Transparent. If you pick White or Background Color, the Layer
Manager shows a single layer named “Background.” If you pick
Transparent, however, the single layer is named “Layer 1”—in this
case, the image (typically an animation file) has no Background layer.
If you cut, delete, or move a selection on the
Background layer, the “hole” that’s left is
filled with the current background color (as
shown on the Color tab). The same operations
on a standard layer leave a transparent hole.
Many standard operations, such as painting, selecting and moving,
Clipboard actions, adjusting colors, applying effects, and so on, are
possible on both the Background layer and standard layers.
Others, such as rearranging the order of layers in the stack, varying
layer opacity (transparency), masking, or creating animation frames,
only work with standard layers.
Once an image has more than just a background layer, the layer
information can only be preserved by saving the image in the native
PhotoPlus (.SPP) format. Multiple layers are merged when you export
an image to a standard “flat” bitmap format like .JPG or .BMP. In
general, we recommend that you save your work-in-progress as .SPP
files, and only export to a different file format as the final step.
Basic layer operations
To select a layer, left- or right-click on its name in the Layer Manager
tab. The selected layer is now the active layer.
To create a new standard layer above the active layer, click the
New Layer button on the Layer Manager tab, or right-click a layer
name and choose New…. To clone the active layer and its contents as a
new standard layer, choose Duplicate... from the Layers menu.
To convert the Background layer to a standard (transparent) layer,
right-click “Background” on the Layer manager tab and choose
Promote to Layer. The layer’s name changes from “Background” to
“Layer <number>.”
To remove the active layer, click the Delete button on the Layer
Manager tab. (You can delete the Background layer, as long as it’s not
the last layer.)