2.2. Using the Layerdialog

Overview

Every layer appears in the dialog in the form of a thumbnail. When an image has multiple layers as components, they appear as a list. The upper layer in the list is the first one visible, and the lowest layer the last visible, the background. Above the list one can find characteristics related individually to each layer. Under the list one can find management buttons for the layer list. A right-click in a layer thumbnail opens the Layer menu.

Layer attributes

Every layer is shown in the list along with its attributes. The main attribute is the name of the layer. You can edit this by a double-click on the name or the thumbnail of the layer. In front of the thumbnail is an icon showing an eye . By clicking on the eye, you toggle whether the layer is visible or not. (Shift-clicking on the eye causes all other to be temporarily hidden.) Another icon, showing a chain , allows you to group layers for operations on more than one layer at a time (for example with the Move tool).

[Tip] Tip

In the case of an animation layer (GIF or MNG), the name of the layer can be used to specify certain parameters : Layer_name (delay in ms) (combination mode), for example Frame-1 (100 ms) (replace). The delay set the time during the layer is visible in the animation. The combination mode set if you combine with the previous layer or replace it: the two modes are (combine) or (replace).

Layers characteristics

Above the layer list, it is possible to specify some properties for the active layer. The active layer is the one highlighted in blue. The properties are : "Layer mode", "Keep transparency", and "Opacity".

  • Layer modes: The layer mode determines how the layer interacts with the other layers. From the combo box you can access all the modes provided by GIMP. The layer modes are fully detailed in the Glossary.

  • Keep transparency: If you check this option the transparent areas of the layer will be keeped, this even if you have checked the Fill transparent areas option for the Bucket fill tool.

  • Opacity: By moving the slider you give more or less opacity to the layer. With a 0 opacity value, the layer is transparent and completely invisible. Don't confuse this with a Layer Mask, which sets the transparency pixel by pixel.

Layer management

Under the layer list a set of buttons allows you to perform some basic operations on the layer list.

  • Edit layer attributs: You can change here the name of the active layer in the list.

  • New layer: You can create here a new layer. A dialog is opened where you can enter the Layer name, perhaps change the default Height and Width, and choose the Layer fill type that will be the new layer's background.

  • Raise layer: You can here move the layer up a level in the list. Press the Shift key to move the layer to the top of the list.

  • Lower layer: You can here move the layer down a level in the list. Press the Shift key to move the layer to the bottom of the list.

    [Tip] Tip

    To move a layer at the bottom of the list, it may first be necessary to add a transparency channel (also called Alpha channel) to the Background layer. To do this, right click on the Background layer and select Add Alpha channel from the menu.

  • Duplicate layer: You can create here a copy of the active layer. Name of new layer is suffixed with a number.

  • Anchor layer: When the active layer is a temporary layer (also called floating selection) shown by this icon , this button anchors it to the previous active layer.

  • Delete layer : You can here delete the active layer.

More layer functions

Other functions about layer size are available in the Layer Drop down menu you get by right clicking on the Layer Dialog. You can find them also in the Layer sub-menu of the image menu.

You will find merging layers functions in the Image submenu of the Image menu.

Clicking-and-dragging layers

Click and hold on layer thumbnail: it enlarges and you can move it by dragging mouse.

So you can put this layer down somewhere else in the layer list.

You can also put the layer down into Toolbox : a new image is created that contains this layer only.

Finally, you can put the layer down into another image: this layer will be added to the layer list, above existing layers.