The quality of sponge depends mainly on the following points

1. See with eyes: the more delicate the sponge's appearance, the smaller the stomata, the better.

2. Hand pinch can quickly rebound, fluffy sponge is better, feel stiff sponge is inferior. (Sponge factory calls dead or closed bubbles)

3. The sponge pulled by hand has a lengthening rate of at least 60%-80%. After stretching out the hand, the sponge immediately restores its original length.

4. Normal sponges have a slight odor when sniffed, but the odor is intolerable when using inferior raw materials.

5. Sponge teared by hand is not easy to tear. It must be jerry-building to break it with a little finger. (Sponge manufacturers call tearing strength)