Tom, the fact that coffe can be used as a developer is not inconvenient for me, or ignored by me. My point was in comparing a coffee-based developer to those made from known, quantifiable chemicals. You've apparently taken offense to my implying cofee-based developers are not real developers, and for that I'm sorry. Coffee-based developers develop film, and that by definition, makes them real developers, so I retract that terminology, but my original question remains unaddressed; what advantages do coffe-based developers offer over developers made from known, quantifiable chemicals, apart from the novelty of being made of household ingredients? I can think of several disadvantages related to using an unknown, unquantifiable developing agent in combination with many, many unknown constituents of unknown properties and/or interactions to make a developer of limited usefulness and poor keeping properties. Put another way, what is the rationale for using cofee in place of a better quality staining developing agent, like catechol or pyrogallol? I mean, aside from the novelty?