Natural leather outperforms other materials due to its flexibility, breathability, wear resistance, resistance to repeated bending, and aesthetic appeal, making it an essential upper material for high-end leather footwear. Its characteristics include:
1. Significant variation in quality across different sections of the hide. Because the skin serves different functions depending on its location on the animal-and develops accordingly-the resulting leather exhibits varying fiber structures, densities, tear strengths, and tensile strengths across different areas. Visual appearance, tactile feel, elongation, flex resistance, and processability also differ significantly.
2. Directional fiber (grain) structure.
Fiber orientation varies across different parts of a single hide. When subjected to tension, different sections exhibit varying rates of elongation; the differences in elongation-and the resulting strain-can be substantial.
3. Breathability.
This property allows moisture (sweat) to escape the shoe interior, ensuring wearer comfort.
4. Good resistance to heat and cold.
5. Excellent wear and impact resistance, combined with ease of processing.
6. Soft yet tough, with good elasticity and flex resistance; it adapts well to physiological needs.
7. Aesthetic appeal, along with properties that facilitate finishing and shaping.