Re: [Gimp-user] How to Lock Alpha Channel to multiple layers?

[Ofnuts <ofnuts gmx com>]

On 11/2/18 10:43 PM, Subsquentual wrote:
> Okay so this is something I figured out a few years ago on an older version of
> GIMP. I'm coming back to it now and have updated it to the newest version as of
> November 2018. And now I cannot figure this out.
>
> So say I have a layer with a picture and I have base colors down. Now I want to
> shade an area of the picture. To do this I open a new layer and choose a dark
> color, usually a grey, and change it's opacity and mode until it looks right to
> me.
> To shade the area, I would have to carefully outline the space on the new layer
> to keep the shading from getting to another area that I do not want shaded.
>
> Now I do all of my coloring on separate layers, like a layer for a shirt, a
> layer for pants, hair, ect that way I don't have to worry about mucking things
> up later.
>
> Locking the Alpha Channel keeps me from going past the area that has already
> been filled. Basically it keeps you from coloring outside of the lines.
> So what I need is to have a layer already filled, make a new transparent layer,
> and lock it's alpha channel to the layer below it, so I can shade easier without
> going out of bounds for that area.
>
> I remember I did it in an older version of GIMP a long time ago, but the new
> interface has me all jumbled and I can't seem to figure it out now.
>
> Any help? Please and thank you...
I don't think there is a way to do that with plain Gimp, but writing a
script to do it is trivial, so you could have such a script before.