GIMP was used to crop the window decoration out of most screen shots to save space and highlight the relevant information.

The notation Image: Colors > Curves means that you should click the Colors menu in the window of the image you are working on and then click the entry called Curves. This type of notation can include more menu levels, of course. Similarly, Layers: right-click > Add an Alpha channel means that you should right-click in the Layers dialog and choose Add an Alpha channel from the menu that appears.

The notation means you should press the corresponding key on the keyboard. means that you press and hold the Control key and then press the U key.

Small caps, as in FEATHER, are used to denote the name of an entry, a button, or a checkbox.

A monospace font like Abstract 1 is used to denote specific text that the user must type into an input field.