Chapter 5. Layers

Table of Contents
What are Layers?
Using Layers
The Layers Dialog
New Layer
Duplicate Layer
Anchor Layer
Delete Layer
Layer Boundary Size
Layer to Image Size
Scale Layer
Merge Visible Layers
Merge Down
Flatten Image
Add Layer Mask
Apply Layer Mask
Delete Layer Mask
Layer Mask to Selection
Add Alpha Channel
Alpha to Selection
Edit Layer Attributes

What are Layers?

When you create an image, it is made up of thousands of tiny pixels, each of which has a color, position, and form the image. It can be hard to work on an image organized at this level. It is also hard to work on an entire image as one block — this is the reason for layers. Layers are in between the tiny size of pixels and the large size of the whole image.

Using layers, you can construct an image of several conceptual parts which can be manipulated without affecting any other part of the image. Layers are stacked on top of each other. The bottom layer is the background of the image and then components in the foreground of the image come above it. Layers can be made to affect the look of layers below them. If, for example, a layer is made translucent, layers underneath will look faded without layer being altered at all. If the translucent layer is later removed, the image below returns to how it looked before.

Figure 5-1. 3D Representation of an Image with Layers

Figure 5-2. The Final Image

Layers are one of the most powerful features in GIMP so it is important to understand how they can be used.