ended up taking a screenshot. of the painting program. OK, this is obviously because I have not used #Krita before and don't know what I'm doing, but... this really ought to be easier. Sigh.
@sil As a KDE person, I don't feel I have to only use QT based things. Gnuimp is still my go to image editor.
Though now I realise that it is over the top for my general use, and maybe I should look at other things. Including QT-centric apps.