Differences Between Printing Methods and Detailed Application Areas

These printing methods are all mainstream printing processes. Their core differences lie in the printing plate, ink, substrate, application areas, and printing effects. Below is a detailed explanation of their differences, accompanied by a comparison table for easy understanding.

1. Offset Lithography (Four-Color Offset Printing)

• Core Principle: Utilizes the principle that "oil and water do not mix." The image areas on the plate are oil-receptive and water-repellent, while the non-image areas are water-receptive and oil-repellent. Water is applied first, then ink. The image is transferred "indirectly" to the substrate via a blanket cylinder.

• Plate Type: Planographic plate (PS plate, CTP plate) — image and non-image areas are almost on the same plane.

• Main Features:

  • Indirect printing: The plate does not directly contact the paper; transfer occurs through a rubber blanket, resulting in less wear and high plate durability.

  • Excellent color reproduction: Typically uses CMYK four-color dot overprinting, capable of reproducing rich colors and gradient layers.

  • High efficiency, low cost: Very suitable for high-volume, high-quality printing.

  
  

• Main Applications: The dominant force in commercial printing — e.g., brochures, magazines, posters, flyers, books, folding cartons.

• Limitations: High demands on paper surface smoothness; difficult to print on non-absorbent materials like plastic; thin ink film lacks three-dimensionality.

2. Flexographic Printing (Flexo)

• Core Principle: Uses a soft, resilient relief plate. An anilox roller precisely controls ink volume, transferring liquid ink directly onto the substrate.

• Plate Type: Soft, resilient relief plate (photopolymer plate, rubber plate).

• Main Features:

  • Broad substrate range: Can print on various materials including paper, plastic film, corrugated board, self-adhesive labels, metal foil, etc.

  • Environmental trend: Widely uses water-based and UV inks, making it more eco-friendly.

  • High printing speed: Well-suited for roll-to-roll continuous printing.

  • Thicker ink film: Vibrant colors, but dot gain is more pronounced. Traditional flexo image sharpness is lower than offset.

  
  

• Main Applications: The king of packaging printing — e.g., food packaging bags, flexible packaging, corrugated boxes, beverage labels, plastic bags. With technological advances (e.g., HD flexo), it is expanding into some commercial printing areas.

3. Gravure Printing

• Core Principle: The image areas on the plate are recessed (engraved cells). During printing, the entire plate cylinder is immersed in an ink fountain. A doctor blade scrapes off the surface ink, leaving ink only in the recessed cells, which is then transferred to the substrate under pressure.

• Plate Type: Steel cylinder with engraved or etched recessed cells.

• Main Features:

  • Thickest ink film: High color saturation, rich layering, strong three-dimensionality, unique tactile quality.

  • Extremely stable print quality: Cylinder-to-cylinder printing; plate durability is extremely high (millions of impressions); color consistency across the entire run.

  • Very high plate-making cost: But per-unit cost is very low for mass production.

  • Fast ink drying: Mostly uses volatile solvent-based inks.

  
  

• Main Applications: Ultra-high-volume, high-quality printing — e.g., banknotes, stamps, securities, high-end cigarette/alcohol packaging, fine art albums, plastic film (food, daily chemical packaging).

4. Letterpress Printing

• Core Principle: The image areas on the plate are raised, while non-image areas are recessed. During inking, ink is applied only to the raised areas, which are then pressed directly onto the substrate. Traditional movable type printing is a typical example.

• Plate Type: Rigid relief plate (traditional lead type, photopolymer relief plate, copper-zinc plate).

• Main Features:

  • Edge embossing effect: High printing pressure creates a slight raised impression visible on the back of the paper.

  • Solid ink coverage: Colors are full and dense, but not as smooth as offset.

  • High flexibility: Can print on unconventional materials.

  
  

• Main Applications: Traditional and specialty printing. Now largely replaced by offset and flexo. Currently mainly used for: hot stamping/embossing die production, self-adhesive labels, letterheads, business cards, vintage-style artistic prints.

5. Screen Printing

• Core Principle: The printing plate is a mesh screen (nylon, polyester, stainless steel) with fine openings. Image areas have open mesh, while non-image areas are blocked by photosensitive emulsion. A squeegee pushes ink through the open mesh onto the substrate.

• Plate Type: Screen mesh stencil.

• Main Features:

  • Very thick ink film: Extremely high opacity; light colors can be printed on dark substrates.

  • Unrestricted substrate shape: Can print on almost any shape and material — flat, curved, cylindrical surfaces, etc.

  • Wide variety of inks: Can use various specialty inks such as foaming ink, fluorescent ink, reflective ink, etc.

  • Lower production efficiency: Better suited for small batches and high variety.

  
  

• Main Applications: Specialty and industrial printing — e.g., T-shirt printing, glass bottles, ceramics, circuit boards, billboards, toys, textiles, panel nameplates.

6. Watermarking (Flexo Watermark)

• Note: "Watermark" here typically refers to "flexo watermarking," a special application of flexographic printing.

• Core Principle: Uses a specially made flexo watermark plate (relief plate). During papermaking or when the paper is damp, pressure is applied to create translucent patterns on the paper. It does not use ink but instead forms the image by altering the fiber density of the paper.

• Main Features:

  • Tangible relief: Visible when held up to light; feels like a raised pattern to the touch.

  • Strong anti-counterfeiting capability: A traditional security anti-counterfeiting technology.

  
  

• Main Applications: Anti-counterfeiting and premium paper — e.g., banknotes, passports, important documents, high-grade stationery, trademarks.

For technical questions or sample requests, please contact our online engineers.

Summary Comparison Table

In Simple Terms:

• For regular books, magazines, and brochures → Choose Offset Lithography.

• For packaging bags and corrugated boxes → Choose Flexo or Gravure (depending on volume and quality requirements).

• For banknotes and high-end cigarette packaging → Choose Gravure.

• For printing on T-shirts or cups → Choose Screen Printing.

• For translucent patterns like those on banknotes → Choose Watermark.

• For hot stamping or vintage raised effects → Choose Letterpress.

(This article is for reference only. For technical questions, please consult an online engineer.)