union two or more layers without duplication?

[rich2005]

Quote:...I thought gimp was more advanced then it is.  I understand the work arounds, and will learn them.. wondering how you put in a request for some new gimp coding.  its there for selections.... now it just needs to be for full layers...

Gimp is a great application full of features. I have been using it since version 2.2 and still do not know all the ins-and-outs. Not many things in this world you get for free, including advice. Even etch-a-sketch costs.

Want to union selections to remove the over lap? One way is shown here. 






Direct link: https://youtu.be/jq9KM3p1ZJQ  duration about 3 minutes.

No layer masks in this but using layer masks is something you should try and grasp. It is non-destructive. Who knows when you might come back to an image to make adjustments.

Edit:
I use a pretty sloppy way of selecting just a layer, that is the way I do it.  (select -> all picks the whole canvas regardless of active layer not true, do not know why I wrote that: although no way to choose a mode). 
Digging through my old files, there is a script for just selecting the boundaries of an active layer. Attached. It might be useful to someone.
Menu entry is bottom of the Select menu. The usual, unzip. Put layer-to-selection.scm in C:\Users\"yourname"\AppData\Roaming\GIMP\2.10\scripts