mmmmmk well here's a desktop version of the Calvin an Hobbes picture I coloured. This is 1280 by 768, which is my desktops size, I've posted another in scraps which is 1440 by 900 if that's closer to your desktop Edit
Unfortunatly I'm now unable to make new desktop sized images as I've lost my original (and only) copy in layered format. I apologise for that.
So feel free to use it, and don't take credit for it please, The lineart was done by
NOT me, I just coloured it
and the BG was a random google photo of a sunset in Africa.