C41 Secrets

This was something that Qin Wen had not yet sent out.

"Why is the letter red?" The County Magistrate Ge asked curiously.

Not only was it red, but the letter was also covered with exquisite wooden cotton.

Su Mu smiled. "This is my trick. Take the colorful flowers, dry them and grind them into powder. Then use a small amount of warm water to wash the powder