How to distinguish between printed and original calligraphy and painting?

Generally, printed matter is dull in color and ink, and the ink effect is dull and unnatural, and there is no trace of pen (even if water is scratched on rice paper, it will leave traces). But the painting and calligraphy industry is mixed, and printed matter is just one of them. If you want to tell the difference, I hope you can draw it yourself first (it is relatively easy to tell the difference after knowing the ink effect). You can also ask some teachers of the local Artists Association Book Association to see if they can help you.