Beginning in the mid-2000s, some iMac models shipped with an “official” cleaning cloth that was referenced in the iMac manual:
“Cleaning Your iMac Display. Use the cloth that came with your iMac to clean the display… Dampen the cloth that came with your iMac, or another clean, soft, lint-free cloth, with water only and wipe the screen. Do not spray liquid directly on the screen.”
This version of the cleaning cloth is black microfiber with an Apple logo embossed in the center edge of one side. The packaging places the embossed Apple logo in the corner due to the manner in which the cloth is folded in its clear envelope-style package.