BitmapAppearance
The Appearance dialog fades selected imported images so they can be used as a light reference underlay to trace or draw over, without permanently changing the image.
Fading an Image
Select one or more bitmaps, then drag the Fade bitmap(s) slider or type a percentage. The view updates as you change the value. Use the revert button to restore the original brightness, then Close.
Tip
Only bitmaps are affected — any other objects in the selection are ignored. If the selected images have different brightness values, a "Mixed values" note is shown.