1. Pigment will ooze from the back of the original calligraphy and Chinese painting, echoing the front, and the color drawn by the machine will not reach the back.
2. The work just made has a faint fragrance of ink and pigment. Printed, machine-sprayed, these don't have this taste.
You can try to spray some water with a watering can. Now some micro-jet prints are printed with dye ink. When water is sprayed, it will be printed. If water is not sprayed, it is considered together with the above method.
4. Hand-painted paper generally shrinks after drying, that is, there are some wrinkles. This kind of fold is unique, just like the kind of fold when paper is soaked in water.