PhotoPlus X6 User Guide - Serif

Selecting layer opacity/transparency
Manipulating Images 85
New layers are transparent (they have an alpha channel) , but once you've placed
pixels on the layer you'll be able to select between the layer's pixels (i.e., their
opacity) and remaining transparency.
To create a selection from a layer's opacity/transparency:
• For selection of Opacity:
In the Layers tab, Ctrl-click on the layer’s image thumbnail.
• For selection of Transparency:
Colour Range
As above, but additionally select Invert from the Select menu.
As an intelligent colour selection method, i.e. where selection is based on
"tagging" a specific range of colours or tones in the image, choose Colour Range
from the Select menu.