Both of them have their own advantages and applicable scenarios, and which material to choose depends on specific needs.

Foamed rubber is a kind of material foamed by plastic particles, which has the characteristics of good elasticity, light weight, fast pressure-sensitive fixation, convenient use, free bending, ultra-thin volume and reliable performance.

PP cotton is a commonly used filling material. Although the resilience is not as good as that of sponge, it feels good, has no odor and is non-toxic. The main advantage of PP cotton is soft and comfortable, but it doesn't last long.