7. Layers

7.1. Main Menu

In addition to the image menubar and image right-click menu, you can also get the Layers menu by right-clicking on a layer thumbnail in the Layers dialog. Several of the operations in this menu are also available from buttons in the Layers dialog: resizing a layer, managing layer transparency, and merging layers.

New Layer

New Layer dialog

This dialog comes up when you create a new layer within an image. It is activated by choosing Image->New Layer

Options

Layer Name

Here you assign the layer a name. This does not have any functional significance: it is simply a convenience to help you remember the role you intended the layer to play when you created it. By default, the name "New Layer" is used. If a layer with this name (or whatever name you choose) already exists, after you hit the "OK" button, a number will be appended to the name in order to make it unique, i. e., "New Layer#1".

Width and Height

Here you set the dimensions of the new layer. When the dialog appears, the values are initialized to the dimensions of the image. You can change them, and if you want to use units other than pixels, you can get them using the Units menu to the right. You can't set the position of the layer within the image here, but you can always move it after it has been created.

Layer Fill Type

Here you have four options for the solid color that will fill the layer: the foreground or background colors as shown in the Main Toolbox; white; or transparent.

Duplicate layer

This item adds to the image a new layer that is a perfect copy of the active layer in all respects but two: first, if the active layer is the bottom layer and lacks an alpha channel, one will be added to the copy; second, if any layer parasites are attached to the active layer, they are not copied (if you don't understand what this means, don't worry about it).

Anchor layer

This item anchors the floating selection to the active layer. If the image does not contain a floating selection, this menu entry will be insensitive.

Merge down

This item causes the active layer to be merged with the layer below it in the layer list, taking into account the active layer's opacity and combination mode.

Delete layer

This item removes the active layer from the image.

Edit Layer Attributes

This item is used to change the name of the layer.

Layer Boundary Size

A layer does not always have same size as the image canvas. It can be smaller (consuming less memory) or larger, in which case some parts are hidden. Selecting this item will activate a dialog in which you can set parameters for the layer dimensions: these parameters are Width and Height, or alternatively Ratio X Y. The layer ratio is maintained if the chain symbol has a "locked" appearance. Clicking on the chain symbol will toggle it between locked and unlocked states. You can use a menu to select the units for the new layer boundary size. Offset locates the upper left corner of the layer in the image's canvas. In addition to editing the numbers, you can change the X and Y offsets by dragging the mouse in the interactive image in the dialog. The old layer configuration is shown with a blurred border and the new layer configuration with a hard border.

Layer to Image Size

This item resizes the layer boundaries to match the image bounds, without moving the contents of the layer with respect to the image.

Scale Layer

With this item you can resize the layer and its contents. A dialog appears in which you can set parameters for the layer size. Those parameters are Width and Height or also Ratio X Y. The layer ratio is retained if the icon behind the ratio values is a chain. When you click on this icon, the chain is broken and the original ratio is no longer maintained. You can use a menu to select the units for the new layer boundary size. The Interpolation menu let you choose how the new layer pixels will be recalculated. When you resize the layer content either pixels are added or removed, and a recalculation is necessary. When the new size is smaller, the layer is cropped. When the new size is larger, a transparent area (or the background color if the layer has no Alpha channel) is added around the previous contents of the layer.