Simple and very effective identification method: just look at the back of the page to see if there are different shades of ink on the back of the page There must be an engraving, but there is no copy.

There are many forms of photocopying, such as taking photos, scanning and copying, but no matter which form, it is completed by optical imaging technology and machine printing, and there is no concave-convex bottom plate, so both sides of the printed book are very flat, especially the back of the paper is very clean and tidy, and there will never be any irregular text parts penetrating the paper.

Movable type typesetting books (including wood, mud and lead) are also operated by hand, which is the difference between photocopies or books printed by modern optical principles and books printed by hand in the past.

Extended data:

The copyright of the original photocopy is still the copyright of the original book. Because local printing can save a lot of money, the price is much cheaper than buying the original book.

The reason for using photocopies can be summarized as follows: it is too expensive to buy other people's original books. In order to save money, we completely copied other people's books after obtaining the copyright authorization from others, and marked the copyright as the original publishing house.

Most of the photocopies are English books or ancient books.