• Offset printing, also known as lithography, is to make the page into a regular pattern. When printing, it is transferred to the rubber cylinder to form a reverse pattern, and then printed onto the material from the reverse pattern to form a regular pattern. This can improve the elasticity of the printing pressure. Toughness and impact strength: PC ＞ PMMA, which is a brittle material.
① Advantages: plate making is simple and cheap; The chromatic binding is accurate, the printing plate is easy to copy, and the printed material is soft and soft, so it can be printed in large quantities.
② Disadvantages: Due to the influence of water glue during printing, the color reproduction is reduced and the brightness is lacking. The printing ink on the page is thin (it can only represent 70% of the capacity, so the offset light box poster must be printed on both sides to enhance its color). Special printing applications are limited.
• Note: flat printing line width ≥ 0.05mm, different color nesting accuracy ≥ 0.05mm, material thickness ≥ 0.3mm

• Screen printing consists of five elements, namely screen printing plate, scraper, ink, printing stand and substrate
• The basic principle of screen printing is to use the basic principle of screen printing plate that part of the screen text is ink permeable and part of the screen text is ink impermeable.
Features of screen printing：
① Strong printing adaptability.
② The ink layer is thick and solid.
③ Strong light resistance and bright colors.
④ The printing format is large.
• Compared with offset printing, the limitation of screen printing lies in the smaller level reproduction range, the difficulty in controlling the color stability of color printing, the large overprint error, and the difficulty in printing fine products.
• Note: the width of silk screen line is ≥ 0.15mm, and the positioning accuracy of different colors is ≥ 0.25mm
• Note: flat printing line width ≥ 0.05mm, different color nesting accuracy ≥ 0.05mm, material thickness ≥ 0.3mm