Water-soluble ferrofluids typically have ferrolluid grains ≤20 nm or so in diameter. We argue that one maybe able to use a single liquid coated ferrofluid grain as an "ink drop" of a hypothetical inkjet printer. Such line scale drops may not be best suited for the desktop inkjet printer but may find a niche in other applications such as in tagging commodities to be protected from easy counterfeiting. © 2004 by Marcel Dekker, Inc.