When Herman Miller rolled out the original Aeron Chair in 1994, it also launched a new paradigm in furniture design. Its designers, Bill Stumpf and Don Chadwick, built the Aeron according to what the body needs, not what the eye likes. The result was a chair that looked more engineered than designed. It looked odd, at first—where were the cushions and upholstery?—but not for long. That same year, Paola Antonelli became MoMA’s design curator, and made the Aeron her first acquisition for the permanent collection. In Silicon Valley, especially, it quickly became a status symbol, visually synonymous with the optimism of the dot-com boom.

For all its success, Herman Miller’s executives eventually started to think they could improve the chair. Today they say they have, with the newly remastered Aeron. Unveiled this morning at Herman Miller’s flagship store in New York, the new task chair is the culmination of two years of work, and an expression of two decades’ worth of accrued knowledge. “The chair is totally new, from the casters up,” says Chadwick, who worked on the redesign. (Stumpf passed away in 2006.) For the person sitting in the chair, all that newness should translate to a cushier seat. “It performs better,” Chadwick says. “It provides this glove effect.”

Herman Miller, Inc.

To the untrained eye, the new Aeron doesn't look that all that different from its predecessor. That was deliberate. “One of the concerns, originally, was we needed to preserve the iconography of the chair,” Chadwick says. “It has such a strong visual personality that there was reluctance to changing it very much.” The Aeron doesn’t have customers; it has fans. Not wanting to abandon or confuse them, Herman Miller kept the shape and size of the original Aeron’s back frame.

The real difference is in the chair’s mechanics. Consider the tilt function. CEO Brian Walker compares the tilt on a chair to the engine in a car—and an engine from 2016 will undoubtedly boast better performance than one from 1994. The tilt on the original Aeron works via a rubber coil spring that allows the chair to lean back when you do. But Chadwick says that spring comes with a slight lag, causing users to push backwards for a beat or two before the chair responds. The new leaf spring, adapted from the Herman Miller Mirra chair, is made of strips of glass-reinforced polystyrene resin that bend more responsively. “It always follows you, it’s always in contact with the back,” Chadwick says.

The second noteworthy update involves the membranous weave that stretches across the frame. Herman Miller calls it the pellicle, and Stumpf and Chadwick essentially invented it in the early ‘90s. The pellicle, more than anything, defines the Aeron. At the time of its release, most chairs had tufted, upholstered seats. The pellicle blatantly exposed the chair’s function, which was to support the back and regulate body temperature through breathability.

Herman Miller says it’s now made 7.5 million pellicles—enough to realize how it could make a newer, more supportive one. The tensile strength of the updated “8Z Pellicle” varies across different zones (the original pellicle had a uniform tension) to create more nuanced posture support. “Just pushing on the lumbar isn’t that healthy of a behavior,” says Tom Niergarth, who led production at the new Aeron. “What you really want to do is get below the lumbar, where you can impact the pelvis. We’re trying to tilt the pelvis forward, so the spinal column creates this healthy curve.” The new pellicle pushes more on the lower back, and has more give around the shoulder blades, where desk workers often carry more tension.

Herman Miller made these ergonomic tweaks in pursuit of Stumpf’s original, humble goal for the Aeron: to create a chair that inspires a lack of awareness. “Even back into the late ‘70s and ‘80s, Stumpf was trying to create a chair that was so comfortable that people only thought about what they were trying to accomplish in the chair, not about pressure points or discomfort points,” Niergarth says. You know how when you have a cold, it consumes your entire existence, but when you’re well, you’re blissfully unaware of it? The best task chairs are like that. For all the time and engineering that Herman Miller’s designers put into the new Aeron, they’d really rather you not notice it, at all.