In a paint object that has a visibility mask, you can erase or delete pixels to reveal a clear background; e.g., you can erase at the edge of an image to create faded or torn edges. You can delete or move selections to create transparent areas. If a paint object does not have a visibility mask, areas where you drag the Eraser tool and selections you delete or move, become filled with the current background color and are opaque, not transparent.
When you create paint objects with painting tools or the Render or Create commands, you can select an option to include visibility masks.
White areas of the fish image erased to a clear background
Adding a visibility mask does not change the appearance of a paint object; e.g., white pixels do not become transparent. When a paint object has a visibility mask, you can select Preserve Visibility in the Channels palette. When this option is selected, Canvas X Draw protects clear areas from the effects of painting and image editing.
You can create a paint object in which the image “background” is transparent or opaque.
An opaque paint object contains opaque pixels. If the pixels are white and the paint object is on a white background, you won’t notice that the image is opaque. Still, the rectangular paint object will block objects behind it.
A transparent paint object can have a clear background that does not block other objects.
Painting in an opaque image is like painting on a wall. Painting in a transparent image is like painting on a window.
A rectangle and text are
A transparent background