I do not understand why one would design an icon for a specific target
dimension! The icons on the desktop can be resized. They depend on the theme
(what about low-vision handicaps?), on the size of the panel (if on the
panel), etc.
But, sure, if for some weird reason the icon has to be
Your home-made launchers are in ~/.local/share/applications. The system ones
are in /usr/share/applications/.
Some screens are high-DPI, thus the icon might show up at 32×32, 48×48,
64×64 or even 96×96, but still take the same screen real estate.
Thank you for the illustrated explanations. :-)
The preferred format actually is SVG. Because it is vectorial, icons look
perfect even if huge on a high-definition screen.
You can convert the image to PNG. Using GIMP's export for instance (in the
"File" menu). Well, that is assuming GIMP can load a PMNG image (a format I
have never heard of).
