The Nike Cortez was designed for athletics; it is one of Nike's
first iconic shoes, and was developed by Nike's founder, Bill Bowerman.
The Cortez was released in 1972, and the idea behind the shoe was
that is should be light weight: originally the shoe was manufactured
using nylon/suede for the upper. Present day, the Cortez is bought
more as a casual sneaker rather than as an athletics shoes; therefore,
you can now buy the Cortez in leather and 100% suede.
The image above show's an original Cortez with a Nylon/Suede upper.
As you can see, the upper is mostly made of nylon, with the suede
only used to hold the toes in place. The modern day Cortez - although
looking virtually identical to the original - is produced using
modern manufacturing techniques, such as Phylon midsole, to lower
it's weight even further.