The layering system can be used to create smooth animations using "onion skinning" or layered images and animations.
Please have a look at the layer primer to learn more about layers and it's use.
Adjust Layers
Shows a dialog box, where you can set up adjustments for the layers.
Layers On
Switches the layers on or off to show or hide layers.
Melt Layers (Flatten)...
Will create a new project that looks like the current one with layers enabled, but without using the layers actually.
The function will create a "flattened" project. If at least one layer uses delta frame position (onion skinning) then the function
opens a dialog box where you can define the range of frames to merged. The resulting project will be an
animation then.
Because the layer system uses 24bit modes including alpha transparency for rendering the resulting animation will
be a true color animation and must be reduced to 256 colors to become a new project. If necessary then you must choose how
to deal with color reduction. If at least one layer has an opacity that is not 100% then the destination project will have an
alpha layer enabled.
Export as Image(s)...
Does the same as "melt layers" but stores the results into one or more image files by using a special dialog.
This way you can create image files with alpha that contain more than 256 colors. It is not possible to save layered animations into animation files because
there is no valid file format that supports animations with alpha.