Layers

In image generation and manipulation programs such as Adobe Photoshop® and Macromedia Fireworks®, you can add graphic content in layers. You can think of these layers as films placed over each other; you can manipulate the transparencies of each layer, as well as alter how the layers interact.

Images with layers usually have to be "flattened" and exported as .gif, .jpg, or .png. "Flattening" is simply placing all of the content into a single layer.

Keeping content on different layers allows image content to be updated withoput remaking the entire image— simply update the changed layer and export the image.

This tutorial will use Macromedia Fireworks®, but the techniques used are simliar in most graphics programs.

To create a new image file, Choose "New" from the File menu.

Open the "Layers" palette or window. (Windows-->Layers). Layer 1 is selected.

The pencil icon indicates that the layer can be edited.

The open eye icon indicates that the layer is visible.

Choose a drawing tool. I've chosen the ellipse tool from the tool palette.

The checkerboard pattern indicates that I'm using a transparent background.

The fill color (bucket icon) is green.

Using the ellipse tool, draw a circle on the blank image. The circle will be filled with the fill color.

Also notice that the graphic content now appears in Layer 1.

Now add a second layer to the image by clicking the "New Layer" icon (the folder icon in the Layers palette) or by selecting Insert-->Layer from the menu bar.

From the tools palette, select the ellipse tool again, and change the bucket fill color to bue. Draw a blue circle overlapping the green one.

Notice that the blue circle (Layer 2) appears on top of the green circle (Layer 1). You can change this by moving the layers in the layer palette. In addition, you can alter the transparency of the layers: the "100%" indicator shows the opacity level of the selected layer. And the interaction of the layers can be altered: the default is "Normal," but you can also display the "difference" between layers; other options include "screen," "lighten," "tint")


Here I have moved the green circle (Layer 1) above the blue (Layer 2), changed the opacity to 50%, and chosen to diplay the difference between the layers where they overlap.