When the button is clicked (on state), it appears illuminated. If the button has borders, it may also appear recessed. When the button is released, it returns to its normal (off) state.
- macOS 10.0–10.14Deprecated
This type of button is best for simply triggering actions because it doesn’t show its state; it always displays its normal image or title. This option is called Momentary Light in Interface Builder’s Button inspector.