There are also chronological factors that determine the value of rubbings, which can be verified through rubbings collation. There are usually three eras of rubbings, namely, the writing era, the engraving era and the rubbings era. The first two are basically not too long apart. Usually, the age of rubbings refers to the age of rubbings, which can be judged according to the inscriptions and seals of rubbings themselves. If it is a famous collection, it is more valuable if it has a credible seal. Before that, we must understand the concepts of copying, reprinting, republishing, pseudo-engraving, complementary engraving and ancestor edition. Reprint is relative to the original. Only when you know that a book has been reprinted in a certain place can you call it reprint. However, the situation is more complicated, and it is related to the original work, so we can't judge reprinting casually, because the meaning of reprinting is similar to that of reprinting, which is easy to be confused. Re-engraving is to re-engrave the proofread copy, and its line layout can be the same as or different from the original. Although seal cutting is also a re-engraving, seal cutting is based on the original manuscript, not only the number of words in the line remains the same, but even the taboo words and the surname of the seal cutter are still engraved on it. Therefore, when using duplicate titles, on the one hand, we should pay attention to whether they are duplicated. A forger fabricates a book according to the information in the book, and then the writing and engraving are all false and worthless. The earliest block-printed or rubbings of books or rubbings are the ancestors. If it belongs to ancestral books, orphan books, rare books and rare books, once it is circulated in an orderly manner, it will naturally be expensive. Generally speaking, things are rare, among which rare books and rare books have the highest value. Nowadays, Ming Tuo and early Qing Tuo are all rare books, while Tang Tuo, Song Tuo and Ming Tuo are all rare books. No matter what tablet, as long as it is the early rubbings unearthed in the Qing Dynasty, it is a rare book, and those with inscriptions, inscriptions and collection marks are also rare books.