The effect of deactivating RGBA channels in the channels dialog can be described better
Submitted by Michael Schumacher
The is a Caution! box that tells the readers a tiny bit about the effects of deactivating channels, but this is IMO not enough to grasp what's going on.
Things that should be mentioned there:
- Deactivating RGBA components does not change the way tools work
A brush will continue to paint as usual, changing the pixels of the layer you're working on. The eraser will change the alpha value of the pixels you're working on, ect.
- Activated RGBA components decide which part(s) of a tools action is applied to the layer
Painting black in normal mode on a fully opaque layer does not make the layer go transparent even if the only channel you've activate is the Alpha one - the paintbrush does just not do this - and using the eraser will not change your image if the alpha channel is not active.
Conclusion: the RGBA channels are there to provde a way to changes (that would happen anyway) to the layer components, they are not designed to redirect changes to the activated components.
Version: git master