2, the painting should be "mounted", also known as "mounted back". Refers to the reinforcement or display attached to the mat; To attach (a piece of paper, for example) to a solid material as a binding. That is, paper or silk is used as a foil to decorate calligraphy and painting books, or to repair them to make them beautiful and durable. Where the mounting must be two layers, and the painting and calligraphy face outwards, it is called mounting; A raccoon is used to set off the back with plain paper without dye.