China's environmental protection calligraphy is imbued with genuine ink. How to remove traces?

You can wash it. My oil dripped, so I washed it.

How to dry it after washing is very particular. Hold on.

I won't twist it after washing, because it's wrinkled and I can't use it.

I washed it, took it out of the water and laid it flat on the tile. The tile is flat and will stick tightly to the tile and air dry.