There are many printing methods of plastic package, and letterpress, gravure, screen and lithographic are commonly used now.
The main application of letterpress in plastic package printing is flexography, and it is mainly for plastic film.
Its printing part is protuberant, and all work is on the same plane. The acting part will be coated with ink. Because the blank part is lower, when press the substrates to attach the plate, the ink will be transferred to the substrates. And the work is done. However, because of the irregularity, its surface will have unconspicuous roughness. This is the explicit characteristic of letterpress.
Flexible edition is the main force of letterpress, and it is widely used in newspapers, books and packaging, such as carton printing, packaging cardboard printing, plastic printing, foil print, paper napkin, toilet paper, tissue paper, etc.
Its advantages are high quality, bright color, thick ink layer, clear level and high seal force. And its disadvantages are long cycle and high fabricating cost.
Gravure is also called intaglio printing. The graphic part is lower than the empty part. Depression levels are associated with the levels of the image. The darker the image is, the deeper the depth is. And because the recess depth is different, the amount of ink will be different, and the ink thickness on the product will be different. This is the reason why the color layering will be so obvious.
Gravure is widely used in large batch calendar, such as paper, magazine, newspaper, plastic packaging, as well as securities, stamps, etc. Due to their high color saturation and image levels, gravure occupies a large market share in packaging and printing.
3. Silk screen
The features of silk screen are thick ink layer and variety of substrates. Its substrates can be all kinds of materials and shapes. It is now widely used in metal, plastic, fabric printing, especially in high-grade package.
Offset is mainly used in coated paper, offset paper and color graphic of package, and its main products include calendars, product advertising, brochures, books and other high-grade printings.
Its printing part and blank space has no obvious layout. They are almost in the same plane. Printing part is lipophilic, and the blank part is hydrophilic. By this method, ink will be left on the printing part.