At first glance, you may think this envelope is made of a special treated leather, but it’s far from it. The japanese brand Siwa is known for using a unique technique called washi-suki, a technique used to create a paper from wood pulp and polyolefin achieving a solid textile, which is even water-resistant to a leather degree. This string and button envelop is made of aforementioned soft Naoron and hence exudes a distinct look when carrying your docs and magazines around.