What Are The Three Types Of Printing Plates?

printing plate is the core part of printing process used to transfer ink. According to its platemaking process, material properties and application scene, mainly divided into relief, lithography and gravure. Here are the details:
1.Relief
Definition: The image portion of a plate is higher than the blank portion. When printing, the ink is attached to the raised image surface and transferred to the substrate by pressure.
Typical: flexographic plate (flexographic printing), letterpress.
Features:
Ink transfer method: direct contact with the substrate, ink layer thicker, color saturation high.
Platemaking process:
Flexible plate: photosensitive resin plate or laser engraving plate, low platemaking cost, short cycle (hours to 1 day), suitable for short-run job.
Movable type: traditional lead type typesetting is now mostly replaced by digital technology.
Applicable scenarios:
Flexible plate: food packaging, labeling, carton, flexible packaging, and other areas, especially suitable for high environmental requirements (such as waterborne ink).
Movable type: A small amount of special printing needs (such as artistic writing, digital printing).
Strengths: Flexibility, low cost, good environmental protection. Weaknesses: slightly less accurate than gravure printing, limited ability to restore fine lines and dots.
2. Floor plan
Definition: The image and text parts of the print are almost on the same plane as the blank parts, and printing is accomplished by the principle of oil-water immiscibility (the image and text parts are oily and the blank parts are hydrophilic).
Typical: Offset (PS).
Features:
Ink transfer method: indirect printing, first through rubber cloth to transfer ink to substrate, ink layer uniform, high printing quality.
Platemaking process:
Offset printing: Aluminum-based PS plate, photosensitive imaging technology produced. The platemaking cost are moderate and the cycle is short (a few hours).
Applicable scenarios:
Commercial printing: printing of high-quality colour picture albums, posters, leaflets, etc.
Packaging printing: high-end packaging box, cigarette packages, wine box, etc.
Strengths: High printing quality, good color reproduction, wide range of applications; limitations: The platemaking process involves chemicals and is slightly less environmentally friendly than flexible printing.
3. Concave
Definition: The image portion of a plate is lower than the blank portion. When printing, the ink fills the groove, scrapes the blank part of the ink with a scraper, and then transfers the ink from the groove to the substrate.
Typical representatives: steel gravure, copper gravure, laser engraving.
Features:
Ink transfer method: direct contact with the substrate, ink layer is thicker (is more than 3 times the flexo printing), color saturation is extremely high, detail restoration is accurate.
Platemaking process:
Traditional gravure: Etching plates on copper or steel cylinders surfaces is costly (3-5 times more than flexo printing) and has a long cycle (1-2 weeks).
Laser engraving gravure plate: using laser direct engraving plate material, shortened plate making time, but equipment costs are higher.
Applicable scenarios:
High-end packaging: luxury labels, art albums, cigarette packs.
Bulk printing: security printing of currency, securities, stamps, etc..
Advantages: High printing quality, thick ink layer, high resistance to printing; Limitationss: high seam cost and poor environmental protection (traditional gravure printing uses solvent type ink).
Type comparison summary
Environmental Application of Type Ink Transfer Method to Print Precision and Print Cost
Direct exposure to low, medium and high food packaging, labelling, short-run job
Flat plate Indirect contact (rubber blanket)
Gravure Direct contact high and low luxury packaging, counterfeit-proof printing
Selection recommendations
Short-term job/environmental protection needs: Priority given to low-cost and environmentally friendly letterpress (flexographic version).
High quality color printing: choose lithography (offset printing), with excellent color reproduction and detail performance.
High volume/high end packaging: Opt for gravure printing, gravure printing with thick layers of ink and high resistance to printing, but balance cost with environmental concerns.