It is caused by those semi-transparent (anti-aliased) pixels with (colour) background remaining after the selection - delete. One cure is growing the selection by a pixel to exclude these pixels but with a small image like your example it will leave a hard border.
Ofnuts has a plug-in to give a better removal of a plain colour background ofn-erase-background.py find it at http://sourceforge.net/projects/gimp-too...s/scripts/ Unzip, put ofn-erase-background.py in your user plugins folder, comes with a html file on usage, read first.
There is a thread about it here: https://www.gimp-forum.net/Thread-ofn-erase-background
and with your image + a grey background to see difference a before / after comparison.
Ofnuts has a plug-in to give a better removal of a plain colour background ofn-erase-background.py find it at http://sourceforge.net/projects/gimp-too...s/scripts/ Unzip, put ofn-erase-background.py in your user plugins folder, comes with a html file on usage, read first.
There is a thread about it here: https://www.gimp-forum.net/Thread-ofn-erase-background
and with your image + a grey background to see difference a before / after comparison.