精装书是一种书的装订方式，配有具保护性的硬底封面(普遍采用硬纸板，外覆以织物、厚纸或小牛皮等皮革)。在大陆的图书一般都是简装书，但是简装书不适合保存，精装书就是一种美观，易保存的图书，具有很高的收藏价值，所以图书收藏爱好者和图书馆都喜欢精装书。

Hardcover book is a kind of book binding method, with a protective hard bottom cover (generally using cardboard, covered with fabric, thick paper or leather). Books in Chinese mainland are generally simple books, but the simplified books are not suitable for preservation. Hardcover books are beautiful, easy to preserve books, and have high collection value. So book collectors and libraries love hardcover books.

精装书常见的几种形式：

There are several common forms of hardcover books

一、按书脊形式来分，有方形书脊和圆形书脊两种。

1、 According to the spine form, there are square spine and round spine.

1、方形书脊，其厚度要比书芯显得厚些。由于书芯折叠及索线的原因，书脊的高度要高于书芯，印张越多越明显。因此，方形书脊的精装书不宜太厚，一般适用于20mm以内的书脊。

1. Square spine, its thickness is thicker than the book block. Due to the folding of the block and the cable line, the height of the spine of the book is higher than that of the block, and the more sheets printed, the more obvious. Therefore, the square spine of the hardcover book should not be too thick, generally suitable for less than 20 mm spine.

2、圆形书脊，因前后书贴的地位略有不同，书贴的折叠处略呈半圆形，分布在一个弧面上，其厚度得到平衡。书芯的翻口处与书脊的凸圆形相适应，呈凹圆形。所以较厚的图书采用圆形书脊较好。圆脊书是经过扒圆加工后背脊成圆弧形的，一般以书芯厚度为弦与圆弧对呈130°为宜。圆脊又可分为圆背无脊(只扒圆不起脊)和圆背有脊(扒圆起脊，起脊的高度一般与书壳的纸板厚度相同)两种。

2. Because the position of the front and back book stickers is slightly different, the folding place of the book stickers is slightly semicircular, which is distributed on a curved surface, and its thickness is balanced. The flap of the book block adapts to the convex circle of the spine, showing a concave circle. Therefore, thicker books with a round spine is better. Round spine book is a circular arc-shaped back spine after rounding processing. Generally, the thickness of the book block is taken as the chord and the arc is 130 ° It's better. Round ridge can be divided into round back without ridge (only grilling round without ridge) and round back with ridge (grilling round with ridge, the height of ridge is generally the same as the paperboard thickness of book case).

                                  

二、按用料分，可分为脊面同料和脊面异料两种。

2、 According to the material, it can be divided into two kinds: the same material on the ridge surface and the different material on the ridge surface.

1、脊面同料，即书脊和封面封底采用整片的同一种材料制成。有方脊和圆脊两种。精装面料多用纸、织物、漆纸、漆布等，一般都配有护封。但有一种全纸面印有书名、图案等并压膜裱糊在硬纸板上，这种书多为方脊不带护封。

1. The ridge surface is made of the same material, that is, the spine and the back cover are made of the same material. There are square ridge and round ridge. Hardcover fabrics use paper, fabric, lacquer paper, lacquer cloth and so on, and are generally equipped with protective seals. But there is a kind of all paper printed with the title of the book, design, and so on, and laminating on cardboard, this kind of book is mostly square ridge, without a protective cover.

2、脊面异料，即书脊和封面用不同材料制成，通常以织物作书脊，以纸张裱糊在硬纸版上作封面，这种形式一般多为圆脊不带护封。

2. Ridge surface material, that is, the spine and cover are made of different materials. Usually, the spine is made of fabric, and the cover is made of paper pasted on the hard paper plate. This form is generally round ridge without protective cover.