Re: [Gimp-user] Adding to Quick Mask using a white brush

[Gez <listas ohweb com ar>]

El jue, 05-05-2016 a las 14:15 -0400, Rick Strong escribió:
> I’m trying to add to a Quick Mask using white as both foreground and
> background colours. White is supposed to add to the mask. But it
> keeps removing the mask. In other words, using a white brush deletes
> that part of the mask and reveals the image underneath when it should
> be covering it up. v. 2.8.16
>
> Any ideas?

It looks like you got it wrong.

Think about black and white as 0 and 1 respectively.
In a selection, 0 means "it's not selected" and 1 means "it's
selected".

This is also consistent with layer masks, where black makes pixels
transparent while white makes them opaque.
Since you can produce layer masks from selections, it makes sense that
those values are consistent.

And why are black and white used that way in layer masks? Because masks
work like alpha channels.

So, when you paint white, you're painting the pixels you want to be selected, the ones to be visible.
It makes sense that those are not "masked out" by your quick mask.

Gez.