In flexo and gravure for large roll quantities.
Understand the two main roll printing techniques for packaging films to choose the right printer and avoid costly mistakes.
Flexo and gravure printing are two roll-to-roll printing techniques used for packaging films and large quantities of roll labels. Flexo uses soft relief plates, suitable for runs of tens of thousands or more with lower plate costs. Gravure uses engraved metal cylinders, providing the highest print quality but only justifiable for very large volumes due to the high initial engraving costs.
- composite film bag
- bulk roll labels
- coffee bag with valve
- Snack and candy packaging.
- small batch and sample
- medium roll folding box
When you order printed bags for coffee, snacks, or functional foods in large quantities, the printer will immediately ask: "Do you choose flexo or rotogravure?" This is not a technical question to distinguish between experts and outsiders, but a question that directly affects initial costs and final print quality. Understanding these two techniques helps you avoid making the wrong choice from the start.
What flexo and gravure printing are
Both are roll-to-roll printing techniques, meaning the printing material runs continuously from the start to the end of the production line. This is the primary printing method for composite films (multi-layer films used for bags), roll labels, and pillow bags.
Flexo (flexography): uses soft relief plates made from rubber or photopolymer. The plate receives ink from anilox rollers and then presses onto the material. Each color requires a separate plate. The setup process is faster than gravure, and the plate-making cost is significantly lower. It offers good print quality, vibrant colors, and is suitable for most food packaging needs. Water-based or UV inks can be used, which are more environmentally friendly compared to traditional solvent inks.
Gravure printing: Engraving images into a metal cylinder (usually chrome-plated), ink fills the engraved cells, a blade removes excess ink, and then the material is pressed against the cylinder to transfer the print. It provides the finest details, deep and perfectly uniform colors. The metal cylinder has a very long lifespan, capable of withstanding over 100 million prints. In return, the initial engraving cost is very high and must be done separately for each color.
When to choose, when not to
The decision between flexo and rotogravure revolves around two factors: expected output and print quality requirements.
- Choose flexo when: production is in the range of tens of thousands to hundreds of thousands of units, quick startup is needed, and the cost of making plates is lower, prioritizing water-based or UV inks for food safety or environmental reasons, and print quality is good enough (no need for extremely fine detail like photographs).
- Choose copper tubes when: production is very large (huge batches running long-term), the highest print quality is required with fine details, deep and uniform colors on each meter of film, and the initial engraving cost can be recovered through production volume.
- Avoid using both when: Output is small or in the testing phase. At this point, digital printing is much more economical as there is no need to create a plate or engrave a cylinder.
- Avoid choosing copper pipes for short runs: The cost of engraving the cylinder cannot be recovered on low output, which will unreasonably inflate the cost per unit.
- Not a good choice for medium-sized folding boxes: Offset printing is more suitable for paper and boxes, not roll films.
The key point: both flexo and gravure incur costs for plates and pre-press cylinders. These costs can be recouped through large volumes. If the volume is not large enough, you are paying that fixed fee for too few units, resulting in a very high cost per package.
Costs, time and quantity
The cost of flexo and gravure printing includes two separate parts: the cost of making the plate or engraving the cylinder (paid once for each design version) and the actual printing cost (calculated by quantity).
The actual time from sending the file to receiving the finished film depends on the printing house and the time of year. Add time for making the plate (flexo) or cylinder engraving (gravure) to the production schedule from the start.
Sinh Vũ acts as the creative director: finalizing the packaging structure, building a standard color palette, and preparing files according to the printer's requirements. Sinh Vũ does not guarantee printing prices as this is directly reported by the printer based on the format, number of colors, and specific quantity you provide.
Editing designs on screen is cheap. Editing an engraved axis is very expensive. This is why everything must be finalized before the file leaves Sinh Vũ.
Practical experience of Sinh Vũ
What does Sinh Vũ need from you to get started
To advise on suitable printing techniques and prepare the correct file, Sinh Vũ needs the following information from you:
- Packaging type and materials: Stand-up pouch, pillow bag, roll label, or other? What is the expected film material?
- SKU number: How many design versions need to be printed? Does each SKU have different components and language?
- Expected output per run: This is the determining factor for flexo, gravure, or digital.
- Market and compliance requirements: Is the product sold domestically or exported? Are there special labeling requirements (ingredients, production date, QR code, language)?
- Timeline: By what date do you need the goods in stock? Count backward from there to know when to finalize the file.
- Overall budget: Includes both design and production parts, allowing Sinh Vũ to advise on the most suitable option rather than the theoretically optimal one.
When you have all the necessary information, please send a summary of your needs to Sinh Vũ for specific consultation and to receive suitable direction proposals.
Decision checklist
Topic: Flexo and gravure printing. Sinh Vũ handbook, sinhvu.com
Select each item you find appropriate, then print or save as PDF to take with you.
If you have marked most of the signs above, this is the time to discuss in more detail. Sinh Vũ can help you review and propose a direction.
References
Flexographic vs Gravure Printing: Key Differences (NOUPACK); Gravure vs Flexo cost analysis (Flexopedia); Rotogravure vs Flexographic Printing: Cost Comparison (KYMC); Which Printing Method is the Most Sustainable (Luminite); Sinh Vũ printing guide (BAO-BI.md branch 3).
Frequently asked questions
What is the most important difference between flexo and rotogravure when I choose a printing house?
The key differentiator is the initial cost of making plates and cylinders. Flexo uses soft plates (rubber or photopolymer) so the initial cost is significantly lower compared to copper cylinders that require a separate metal cylinder for each color. Copper compensates with a very high cylinder lifespan and finer print quality, but costs can only be recovered with very large production runs. Before asking the printer, you need to know the expected production volume for each run to choose the right technique.
Can I change the design after the copper tube has been made?
Changing after the die has been cut means redoing the die, which incurs costs for creating a new die for the changed color. This is why Sinh Vũ always finalizes the packaging structure, color palette, and layout before sending files to the printer. Fixing designs on screen is cheap, but fixing a die that has already been cut is very expensive.
Can digital printing replace flexo for small runs?
Yes. For small batches or samples, digital printing does not require plates or cylinder engraving, making it much more economical. When production increases to tens of thousands of units or more, the cost per unit of flexo printing becomes competitive. Sinh Vũ will advise on the appropriate conversion threshold for each specific product.