Frank Series: Natural leather gathered from various places in Europe and finished by a tannery specialized in horse leather in Japan. Oil is combined with dye and interfused into leather in a drum, instead of using it for finishing. The leather is rubbed to make its surface smooth and soft. It retains a natural texture that is different from the ones with surface finish like embossing and pigment-dyeing. Unevenness in delicate color creates richer taste, so that when you look closer you will notice each has a distinctive texture.