there is no certain stable model among the designers for how to be sustainable in practice, and the understanding of sustainability is always a process or a work-in-progress, and varies by who defines what is "sustainable;" farmers or animals, producers or consumers, managers or workers. thus critical scholars would label much of the business-driven discourse on sustainability as "greenwashing" as under the current economic paradigm, "sustainability" is primarily defined as keeping the wheels of perpetual production and consumption turning; to keep the "perpetuum mobile" of fashion running and in perpetual motion.