Difference of the material of Velcro tape--Shereson
Chinlon, namely, whose scientific name is polyamide fibre. The advantages of nylon are high strength, high wearing feature, high chemistry resistance and nice deformation resistance, while the disadvantage is the hard handfeel.
Commonly, the fabric of multiplies of 70D, are nylon, such as 70D, 210D, 420D, 840D, 1680D. They all have bright glossiness and slippery handfeel.
The scientific name is polyester fibre. The characteristics are good air permeability and wet resistance. Still, it has strong acid and alkaline resistance and UV resistance.
Commonly, the fabric of multiplies of 75D, are terylene, such as 75D, 150D, 300D,600D, 1200D, 1800D. The surface is darker than nylon and a little harsh.