Proofreading is a crucial link between prepress and printing in the current printing industry based on computer technology, network technology, new materials, and complex processes. It is an important means of quality control and management in printing production, and is extremely important for controlling printing quality, reducing printing risks and costs. With the digitization of content expression and process control, product cycles are increasingly decreasing and production efficiency is rapidly improving. Therefore, the requirements for quality control and product inspection sampling technology in the printing production process are becoming higher and higher. Emerging digital sampling has emerged and begun to provide relevant standards for printing, providing users with quality standards or acceptance standards for printed products. 1、 Digital proofing and its production process: Digital proofing refers to a new type of proofing technology that is based on a digital publishing and printing system. During the publishing and printing production process, page graphic and text information is processed according to publishing and printing production standards and specifications, and color samples are directly output. That is, using data-driven originals to directly output printing samples. It uses a large format printer to directly output samples through digital means, replacing traditional lengthy sample making processes such as film making and plate printing. A digital proofing system generally consists of a color inkjet printer or a color laser printer, and uses color printing and simulated printing to obtain a verification sample from a digitized original (electronic file). 1. Digital sampling system. The digital proofing system is based on the digital publishing and printing system (CIP3/CIP4), which uses the same page of graphic and textual information (RIP data) to reproduce color graphic and textual information through computers and related equipment and software, and controls the quality of the printing production process. At present, the digital proofing system consists of two parts: a digital proofing output device and a digital proofing software. It adopts digital color management and color control technology to achieve high fidelity consistency between the printing color gamut and the digital proofing color gamut. The digital sample output device refers to any color printer that can output digitally, such as the most commonly used and able to meet publishing and printing requirements in China, which are mostly large format color inkjet printers; Digital proofing control software is the core and key of a digital proofing system, mainly including RIP, color management software, composition software, etc. It completes the digital screening of pages, page assembly, and matching of ink color gamut and printing ink color gamut. The most representative currently is the high-tech BlackMagic digital proofing system that uses true dot technology. 2. The process of digital sampling. The process of digital proofing is: receiving electronic files on the page - RIP - digital proofing. The homework process includes: system settings - electronic file acceptance - assembly of large plates - selection of sample materials - digital sampling. Usually, a set of four color split digital proofing takes 15-30 minutes. A good set of digital proofing software can control multiple digital proofing machines, so the production efficiency is very high. Digital proofing is not only different from the traditional round pressing printing method of sample machines, but also from the round pressing printing method of printing machines. Instead, it is based on the color range of the printed product and the same RIP data as the printed content, using color printing with a larger color gamut space to match the color gamut space