The previous tutorial just covering the interface can be found here.
The list of all my GIMP tutorials can be found here.
One of the main things to remember when working with layers is that they will affect other layers from the top down in your layer list. I haven't mentioned layer blending modes yet, but for layers with a "Normal" blending mode (the default) this means that the top most layer that is visible is what you will see in your image window (see video).
Creating a new layer from scratch is quite simple. There is a "Create New Layer" button along the bottom of the top half of the Layers window. You will then get a "Create a New Layer" dialog that allows you to choose:
- Layer Name
Whatever you want to call this layer
- Width & Height
Dimensions for this new layer (default is the current image dimensions).
- Layer Fill Type
You can have the layer automatically filled with either the foreground or background color, white, or start it as a transparent layer.
This new layer will then be created above the currently active layer in your list. Speaking of "active layer"...
Look closely at the image above: the "Background" layer is active (white border), but there is another layer "New Layer" that is above it and visible. If you tried to paint or adjust the "Background" layer right now, you wouldn't see any of the changes (in fact, you'd just see a black screen in your image window).
To activate a layer, just click on it in your Layer Window list.
VisibilityYou can toggle the visibility of each layer on/off by using the Eye icon to the left of the layer image. This will only affect the layer visibility in your main image window.
Very often I will use the layer visibility toggle to either compare a current layer to a previous one, or to show/hide the effects of a new layer on the ones below it (in the case of using a different blending mode or layer masks - which I will talk about shortly).