What are the advantages of butterflies?

Advantages: Adapting to the characteristics of block printing books, the center of the block is hidden in the spine of the book, and the top, bottom, left and right are redundant pictures outside the column, which is beneficial to protecting the characters in the column. "Preface to the History of Ming Dynasty, Art and Literature" said: "The secret cabinet books are all left by the Song and Yuan Dynasties, and they are all exquisite. It is folded outward on all sides, and the insects and rats can't be damaged. " It shows that butterfly dress is a popular binding form in Song and Yuan Dynasties.

Insufficient:

1, the page is upside down, and all pages with words face inward. All pages are single pages. When reading a page, the first thing you see is the reverse side without words, which is easy to cause pages with words to suck up and bring inconvenience to reading.

2. The spine of the book is stuck with paste, which often makes it easy to disperse.

3. It needs whole carving, whole paper printing and binding.

trait

1, the leaves of the butterfly suit are all simple. When you open it, the back without words always faces people, and the front with words faces inward.

2. The book mouth of each page is attached to the book mouth, and it spreads its wings like a butterfly.

3, the book mouth and the book coat don't need to be sewn, just paste them.