They look like the exact same Dr. Martens…so why is one dramatically heavier? And $60 more expensive

A $180 Dr. Martens boot and a $240 Solovair can look almost identical: same shape, same air-cushioned sole, same strip of rubber wrapping the base. For roughly thirty-five years, they even came from the same English factory. But beneath the surface, they are built according to two completely different ideas of what a boot should be. In 1960, the makers of Dr. Martens turned to the Northamptonshire Productive Society—NPS—to manufacture their new air-cushioned boot. The factory called its version Solovair, short for “sole of air,” and produced Dr. Martens for decades. When that relationship ended in the mid-1990s, Dr. Martens kept the famous name. NPS kept the factory and the knowledge of how the original boots were made. The modern Dr. Martens has no shank and uses a thin foam midsole. It feels comfortable quickly, but as the foam compresses, the support beneath the foot begins to disappear. The Solovair uses a wooden shank and a full-length felted midsole. It starts out stiffer, then gradually shapes itself around the foot. The same divide appears in the leather. Dr. Martens uses a thinner hide covered with a glossy finish, while Solovair uses thicker, more heavily conditioned leather that takes longer to break in. Underneath, the Dr. Martens upper is bonded to the outsole along a relatively narrow strip. Solovair more than doubles that contact area, reinforcing the place where boots often begin to separate and let in water. Two boots grew out of the same factory and the same air-cushioned design. One kept the name. The other kept the craft.