Using channels

The image or document's colour mode determines the number and type of colour channels available to you. Each channel stores colour information specific to it, which, when combined with other channels, brings about the full colour image. For example, a red channel would store only red colour information in RGB colour mode.

Channel information is displayed in the Channels Studio.

Separated out colour channels of a CMYK image.

The colour channels of a CMYK image separated out.

Composited colour channels of a CMYK image.

The composite of the above image's colour channels.

Colour modes and channels

For each colour mode, the following channels are available:

Image and layer channels

The Channels Studio always displays an image's channels when loaded. From an image channel you can:

For any currently selected layer (pixel, mask, adjustment or live filter), the layer's channel(s) are displayed below the image channels. From each layer's channel you can:

Alpha channels

The Channels Studio also displays the alpha channel for the whole image or currently selected pixel, mask, adjustment, or live filter layer. These channels store transparency information, so it's a great place for more advanced masking control.

Pixel selections

Another great use of alpha channels is the ability to store more complex selections that would otherwise be difficult or time consuming to recreate again. The Channels Studio reports your current pixel selection as a channel entry, so by creating a 'new' Spare Channel from that pixel selection you've stored the selection for future use.

Pixel selections and masks

Because alpha channels store both selection and masks, the Channels Studio acts as a great central point for working between masks and selections.

Blend ranges

You can control how specific colour channels of the current layer blend with the underlying layer(s). For more information, see Layer blend ranges.

Editing spare channels

The spare channel that stores your mask can be isolated for editing. This lets you paint and erase directly on the spare channel, as well as apply filters such as Gaussian Blur for softer mask edges.

Channels Studio Visible Channel To hide/show image channels:
Editable Channel To protect image channels from editing:
More button To create a mask or greyscale layer from a current layer's channel:

The new layer is added to the Layers Studio.

More button To invert, clear or fill a layer's channel:
More button To save a selection as an alpha channel:

The selection is stored at the bottom of the Channels Studio as a new 'Spare Channel' entry.

Layers Studio Channels Studio More button To edit a spare channel and apply to a mask:
  1. From the Layers Studio, select a mask layer.
  2. From the Channels Studio, tap the More button on the Mask Alpha layer, and choose Create Spare Channel.
  3. 
Tap the More button on the newly created 'Spare Channel' entry and tap Edit to isolate it.
  4. Edit the spare channel.
  5. Reselect the mask layer in the Layers Studio to exit isolation mode.
  6. 
Tap the More button on the 'Spare Channel' entry and choose Load to Mask Alpha to apply the edited spare channel to your mask.


Before editing a spare channel, you have the option of duplicating the initial spare channel. This procedure is often used to preserve an unedited backup copy of a spare channel before editing the original.

More button To duplicate a spare channel:

The duplicate is stored below the original as a new 'Spare Channel' entry.

More button To rename a spare channel:

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