How is the 'pigskin' used in the shoe lining different from the outer leather?

The outside is cow leather or lambskin, and the inside is pigskin^[1][2][3][4]. Depending on the model, Blanc Sur Blanc uses Cow Leather or Lamb Skin for the upper material, while commonly applying Pig Skin to the lining that wraps around the foot^[5][6][7][8]. Carefully selected leather is used not only for the lining but also for the insole area that touches the sole of the foot^[9].

The pigskin used for the lining is a material suitable for dealing with sweat and heat. Generally, pigskin has fine pores distributed throughout, making it among natural leathers with superior breathability and moisture absorption. It resists friction well while feeling soft to the touch, so when lined inside shoes, it reduces sweat buildup and helps provide comfortable wear against bare feet. On the other hand, the cow leather on the outside firmly maintains the shoe's shape, and lambskin has a smooth grain that softly supports the movement of the instep when walking.

This configuration divides the leather types according to their roles: the outer surface supporting the shoe's shape, and the inside having to withstand sweat and friction.