Each frame in a Springboard file is made up of layers. If you have used other graphic editors, such as Photoshop, Illustrator, Corel Draw, or Paint Shop Pro, you may already be familiar with the layer model. If not, you can think of layers like pieces of paper that are held together in a stack, with the following properties:

• Layers on top obscure the ones underneath.
• Layers can be moved around horizontally and vertically within the frame. Any part of a layer that sticks out beyond the frame is clipped off (though you can see those parts with View > Single Frame).
• Layers can have transparency. Full transparency is like cutting a hole in the layer with scissors; whatever is underneath will show through. Layers can also be partly transparent, like a drawing on tracing paper.

The layers in the current frame are shown in the Layers palette:

There are two basic layer types: bitmap layers, that contain a grid of colored dots ("pixels"), and vector layers, that contain a "vector object" that can be changed at any time, and which converts itself to pixels whenever it is drawn on the screen.

Springboard's drawing tools work with either bitmap or vector layers, but not both. The "natural-media" tools draw onto bitmap layers, while the vector tools create new vector objects on their own layers.

Some quick tips and links on working with layers:

• Layers can have colors assigned with them in various ways.
• You can change the name of a layer, and its other properties, with the Layer Properties dialog.
• You can use the Layer > New command to add more global or local overlay layers. Make an overlay in a different color for each kind of information you want to keep - e.g., for showing object motion, areas that will require special effects, transitions, etc.
• You can reorder and nest layers by dragging them in the Layers palette.
• If you need more room outside the frame to grab vector handles or to start drawing strokes, use View > Single Frame.
• To select one layer out of many, right-click in the frame where the layer has some content, and choose Select Layer from the context menu.