Flayed1
If you were using 8thjinx's grunt training map, it should already be sized and formatted for the clipboard. If you are using mine from Arlo's site, my maps were made for printing in a higher color {24-bit}{more color diversity} and many of the sizes were bigger because of the legend on each map.
I have taken my grunt training map and cropped off the legend, sized it to 512 x 512 pixels, changed it to 256 color and converted it to a bitmap from a jpeg format. The attached map
is ready to be placed in the clipboard maps in the game.
I believe the clipboard image parameters are the same as they have been in the past. Goodluck and let me know if I can be of any help.
BTW, you can take a screen shot in game or use the terrain editor in the game to create images that you want to place in the clipboard maps feature.
Cheers, One-eye