Why is Pu 'er tea wrapped in two layers of cotton paper?

Tea cakes are packed in double-layer cotton paper, which is stronger than single-layer cotton paper. It also has a good fragrance gathering effect. The outer cotton paper is made by local Dai people in Menghai, which is flexible, tensile, insect-proof, corrosion-resistant, not easy to change color, natural in wood and good in air permeability. The inner paper is food-grade white paper to ensure the health and safety of tea.