Putting images in an array

So lets say i have 76 comic covers i'd like to make a wallpaper. Is there an easy way to make them one large file with all the covers? Or Do i have to do it piece by piece? something like



but with comic books instead of albums.

I can't see the picture but I know what you mean. I think you've got to do it one by one: I don't know of any way to do it automatically.