What does the word gravure in bag printing mean?

People know the word bag, but little is known about gravure related to bag printing. Now I’m here to explain to you what is gravure. In the mid-15th century, the wounding of gravure plates was first done by hand. Hand-cut with a knife on a copper plate or steel plate. In the early 17th century, chemical etching was used for the production of gravure plates. The specific method is: first apply a layer of acid-resistant and anti-corrosion wax layer on the surface of the copper skin, and then use a sharp steel needle to draw on the wax layer. The one-step etching process is in contact with an acid solution, thereby forming a concave trace. The invention and application of a number of technologies during the 18th and 19th centuries laid a solid foundation for the great changes in the gravure making process. These include: the discovery of potassium dichromate with photosensitivity in 1782; the invention of photographic technology in 1839; the discovery of the difference in physical properties before and after exposure to potassium dichromate in 1839; the carbon paper transfer method in 1864; the birth of gravure technology in 1878, It was officially put into production in Vienna in 1890. The photogravure method uses photography to make films and uses carbon paper as an intermediate, which completely replaces manual engraving and greatly improves the quality and speed of plate making. Low-grade prints, and the subsequent appearance of the Boumeran platemaking method also failed to fundamentally improve the quality of gravure. Vacuum packaging bags, tea packaging bags until the emergence of the electronic engraving gravure process, so that the gravure plate no longer simply relies on one-dimensional changes to reflect the depth of the layer (photogravure method The plate making method relies on the change of the surface area of the cell), and the electronic engraving gravure relies on the simultaneous change of the surface area and the depth of the cell to reflect the depth of the layer, which makes it possible to use the gravure process to replicate the high-grade work that is mainly based on layers. Especially after computer technology is widely used in the field of gravure, gravure plate making and printing technology are even more powerful. In terms of gravure plate making, it was the first to realize the film-free technology. Today, the offset printing process is still vigorously promoting the CTP technology. The CTP in the gravure field has been successfully operated for nearly 10 years; the second is the successful use of digital proofing technology. Today, digital proofing technology has been widely accepted in the field of gravure and plays an indispensable role in production.