I search a little how change folders background and icons with ios 4.2 on my ipad and it seems I can only find some way using special hack file through itunes or with jailbreak. There's no simple standard way to do it?
I have seen a complicated manipulation by creating an image with an exact size and exact name and in a series of folders with also exact names. That manipulation didn't seem involves Jailbreaking but I'm not sure. Anyway I don't know the names equivalent for ios 4.2 and image size for iPad. But I'm tempted even if I understand the ugly black background is to let an idea of contents through mini icons but it's so small that I feel it pointless.