When it comes to printing for packaged and functional products, selecting the right printing method can greatly influence the final outcome. Offset printing and flexographic (flexo) printing are two widely used printing techniques, each offering unique benefits tailored to different packaging needs.
Offset printing has long been the industry standard for large-volume, high-quality jobs, known for its ability to deliver sharp and vibrant prints on a variety of materials.
On the other hand, flexographic printing is increasingly popular, particularly for packaging and non-porous surfaces. Its versatility and efficiency in working with different substrates make it a strong option for projects that need flexibility and adaptability.
In this blog, we’ll break down the key differences between offset and flexo printing, focusing on how each method can meet the specific demands of your packaged products, so you can make an informed decision for your next printing project.
What is flexographic printing?
Flexographic printing, or flexography, uses flexible polymer plates with raised images. Ink is applied to these raised surfaces to transfer detailed prints onto a range of materials.
The process involves wrapping these plates around rotating cylinders, allowing for the efficient application of ink and the transfer of images onto continuous rolls of substrate. This method is similar to letterpress printing but incorporates modern advancements.
- Substrates: Flexible relief printing is versatile and can handle a wide range of substrates. It excels on non-porous materials like plastics, films, and foils, as well as flexible materials such as food-grade papers.
- Quality: Flexography is known for producing high-quality prints with consistent color and sharp detail. While it may not reach the same level of fine detail as some other methods, its flexibility and reliability often compensate for this in practical applications.
- Uses: Flexo printing is frequently used for packaging, labels, and flexible materials. Its capability to print on diverse substrates makes it perfect for food packaging, consumer goods, and industrial labels.
What is offset printing?
Offset printing is a technique where an image is first transferred from a metal plate to a rubber blanket before being applied to the printing surface. This “offset” step is key to the process, as it ensures even ink application and protects the printing surface.
The rubber blanket molds to the surface, allowing for consistent quality even on slightly textured materials. Offset printing is ideal for large-scale production, where maintaining uniformity and precision across many copies is essential.
- Quality: What makes offset printing stand out is its ability to produce crisp, vibrant images with great color accuracy. Whether you’re working with intricate designs or bold colors, this method ensures that every detail comes through clearly.
- Substrates: Offset printing is versatile and works well on various materials, from different kinds of paper to cardboard and some plastics. It performs best on smooth, flat surfaces, where it can produce clean, precise prints.
- Uses: Offset printing is widely used in the production of high-quality materials such as magazines, brochures, books, and posters. It’s also a popular choice for business cards, stationery, and packaging.
Similarities between flexo and offset printing
Despite their differences, flexo and offset printing share several common features. Here’s a look at what these two methods have in common:
- Both techniques rely on printing plates to transfer images, with the image being engraved onto these plates.
- Both use wet inks, which are applied during the printing process.
- Each method is versatile in terms of the substrates it can handle, accommodating a broad range of materials.
- Both are particularly effective for large-scale printing jobs, making them ideal for high-volume production.
- Both techniques involve a significant setup time before production begins, ensuring everything is aligned and ready for consistent results.
Related: Offset printing vs digital printing
What are the differences between flexo printing and offset printing?
There are also several important difference between flexography and offset printing and here are some of them:
- Printing plates
- Ink systems
- Materials used
- Setup cost
- Run length
- Print quality
- Maintenance
- Environmental impact
Difference 1: Printing plates
Flexographic printing, commonly known as flexo printing, uses flexible photopolymer plates. These plates are wrapped around rotating cylinders and feature a raised image that gets inked and transferred directly onto the material.
The flexibility of flexo plates allows for printing on a variety of surfaces, from absorbent to non-absorbent materials. For each color, a separate plate is used, with every plate mounted on its own printing station. Flexo plates are highly durable and can be reused multiple times if stored properly.
On the other hand, offset press printing involves an additional step. Instead of applying ink directly from the plate to the material, the ink is first transferred to a rubber blanket, which then presses the image onto the surface.
This “offset” process gives the method its name. Offset printing plates are usually made of aluminum and can be utilized in both flat-bed and rotary presses depending on the setup.
Difference 2: Ink systems
In offset printing, the ink system is primarily based on the CMYK color model—cyan, magenta, yellow, and black—where each color has its own printing station. Spot colors can also be mixed from these four standard process colors.
Depending on the specific job and the substrate, offset inks can either be water-based or UV-curable. While offset inks produce vibrant, high-quality results, they often require longer drying times, especially for water-based inks.
Flexo printing also uses process colors but typically includes additional stations for spot colors, which can be pre-mixed or mixed on-site. Flexo inks are highly versatile, ranging from water-based and UV-curable to solvent-based types.
UV-curable inks are advantageous for flexo printing since they can remain in the press without needing to be cleaned out at the end of a shift. However, water-based inks require careful removal and cleaning to prevent drying on the rollers and trays, which could cause clogging.
Difference 3: Materials used
Offset printing excels when used on smooth, flat surfaces like paper, cardboard, metal, vinyl, and cellophane. This method is often used for producing high-quality products such as magazines, books, brochures, posters, and newspapers.
Offset presses usually require a second pass for double-sided printing, and additional finishing processes like folding, die-cutting, laminating, or creasing are often done separately after the initial print run.
Flexographic printing, by contrast, is far more versatile in terms of materials. It works well on both absorbent and non-absorbent surfaces, including plastic, foil, fabric, metal, cellophane, and cardboard.
This flexibility makes flexo ideal for packaging applications, such as labels, envelopes, retail bags, wallpaper, and food wrappers. Many flexo presses come with built-in finishing options like die-cutting or laminating, enabling the entire process to be completed in a single pass.
Difference 4: Setup cost
Flexography often involves higher initial costs due to the need for custom plates and complex machine preparation. This investment can be justified for extensive production runs where the plates offer long-term use.
In contrast, offset lithography usually has lower upfront costs. The process to prepare plates and equipment is more straightforward and economical, making it suitable for smaller-scale projects or initial print runs.
Difference 5: Run length
Flexible relief printing excels in long production runs, operating at speeds of up to 2,000 linear feet per minute (fpm). This high speed makes it ideal for large orders, ensuring efficiency and cost-effectiveness for extensive print jobs.
Offset lithography is also suited for large volumes, with presses capable of handling up to 18,000 sheets per hour, or 300 sheets per minute. While setup may be more time-consuming, offset printing offers excellent consistency and quality for high-volume projects.
Difference 6: Print quality
For flexography, the results are reliable across various surfaces. It’s adept at producing clear and consistent prints, especially useful for packaging and flexible materials.
Offset litho printing excels in producing high-resolution images with vivid colors. This method is preferred for projects requiring detailed graphics and rich, accurate hues, such as magazines, packaging and premium brochures.
Difference 7: Maintenance
Flexible relief printing demands more frequent maintenance. Regular cleaning of the plates and ink systems is necessary, especially with water-based inks that can dry and cause blockages.
Offset lithography requires less maintenance. Although regular cleaning is needed, the process is simpler, leading to easier long-term care and reduced maintenance efforts.
Difference 8: Environmental impact
Flexographic printing can vary in environmental impact. It uses water-based and UV-curable inks, which are generally less harmful, but some solvent-based inks release volatile organic compounds (VOCs). Efficient use of materials in flexo printing can reduce waste, as it handles continuous rolls, minimising offcuts.
Offset lithography also has environmental considerations, particularly due to the chemicals used in plate-making and traditional inks that contain solvents and VOCs. However, many offset printers are shifting to eco-friendly practices, such as using vegetable-based inks and recycling, to reduce their impact.
Final Verdict: flexo vs. offset printing
Flexographic printing generally outperforms offset printing in flexibility and efficiency. It’s designed for high-speed production, making it ideal for large-scale tasks such as packaging and labels.
Flexo’s ability to handle various materials and its cost-effectiveness for large volumes give it a significant advantage for projects requiring quick turnaround and adaptability. Plus, its integration with digital technology for hybrid solutions adds to its benefits.
On the other hand, offset printing is known for its superior print quality, especially for detailed graphics on paper. It produces high-resolution images with vibrant colors, making it the top choice for high-quality brochures, magazines, and other print materials where visual detail is crucial.
In summary, if you prioritize versatility, speed, and efficiency, especially for packaging, flexographic printing is likely the better option. However, for the highest quality in detailed graphic work, offset printing stands out.
Consider the specific requirements of your project and your future needs when selecting the right printing technology for your business.