1。 Taobao sells it. Search for non-woven fabrics and it will come out, about 50 cents (30CM x30CM). Imported ones are thicker than domestic ones and can be washed. Domestic ones are thinner, but they can't be washed. See what you need.

2。 This kind of cloth is not easy to find in the market. I didn't see any where it was sold. There should be one in DIY handicraft shop. They are sold here in lattice shop. Five dollars for three pieces, quite dark. It is much cheaper to buy it online.