User Guide

Canvas 12 User Guide
When you make a new paint object by pasting a non-rectangular selection copied from an image,
Canvas makes a channel mask to hide white pixels surrounding the selection.
Original Channel mask from
alpha channel
Vignette
Preserving transparency in images
Select the Preserve Visibility check box in the Channels palette to preserve transparency when you
paint or apply filters to an image. The Preserve Visibility check box is available when you edit a paint
object that has a visibility mask. A paint object has a visibility mask if it was created with a
transparent background, or if you applied a visibility mask with the Add Visibility Mask command.
If a paint object has an opaque background, the Preserve Visibility check box is disabled.
To preserve transparency while editing an image:
When a paint object is in edit mode, select Preserve Visibility in the Channels palette. When
selected, you can paint and edit the image without affecting clear areas or reducing the
transparency of partially transparent pixels.
The Preserve Visibility option affects all aspects of image editing. When Preserve Visibility is selected,
pasted selections do not affect clear areas. Also, a pasted selection will match the transparency of the
existing pixels when you defloat the selection.
If an image is completely clear (contains no colored pixels), you cannot alter the image when
Preserve Visibility is selected.
You must deselect Preserve Visibility to paint in clear areas of an image. Then, if you want to edit the
painted areas, select Preserve Visibility again.
For example, you can deselect Preserve Visibility and paint airbrush strokes in a clear image. Then,
select Preserve Visibility and you can paint over the airbrush strokes to change their color, without
losing the soft edge or “spilling” color into clear areas.
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