Flexographic printing is one of the most used methods for printing on flexible packaging materials, including plastic films, foils, and paper. Known for its speed, cost-efficiency, and versatility, flexographic printing supports a range of applications from consumer-packaged goods (CPG) to healthcare products and sterile medical devices.
Flexographic printing continues to evolve with advancements in materials, automation, and prepress technology. For converters and brands alike, understanding these options supports smarter decisions that enhance quality, speed-to-market, and sustainable production.
Jump directly to a section below:
- Flexographic printing process
- Flat plates vs ITR sleeves
- Solvent-based vs water-based inks
- Surface vs reverse printing
- Rewind & Unwind figures
- Flexo vs gravure vs digital printing
- Advantages of flexo printing with Eagle
The Flexographic Printing Process
Flexographic printing is a rotary relief printing method widely used in the packaging industry. Flexo printing is valued for its ability to handle long runs, quick changeovers, and a wide variety of substrates with minimal waste. It uses flexible photopolymer plates or in the round (ITR) sleeves to transfer ink onto a substrate through a fast, continuous process. Here’s how it works:
- Artwork Preparation: Your artwork is laid out according to the package dieline, size, and type of material to be printed. At Eagle, our in-house graphics team reviews and prepares your artwork files for production.
- Proof Review & Artwork Approval: Once your artwork file has been processed, you will receive a print-ready proof to review for accuracy and approve. Eagle provides a digital PDF proof and hard copy proofs are available upon request.
- Image engraving: Once the proof is approved, artwork is separated by color and each color layer is engraved onto a printing plate or sleeve. At Eagle, our in-house engraving capabilities reduce lead time, cost, and ensure great quality of plates and sleeves from the start.
- Plate or Sleeve Mounting: Plates or sleeves are mounted onto cylinders for the printing press. Eagle uses a digital plate mounter to support quick turnarounds and accuracy of registration for complex artwork.
- Ink Transfer: After the plates or sleeves are mounted and cylinders are set up on the press, it’s time to print! An anilox roller meters ink from the ink pan and transfers it to the raised image on the engraved plate. Eagle uses both water-based and solvent-based ink systems.
- Substrate Contact: The inked plate presses against the substrate, transferring the image to the material.
- Drying: The ink is rapidly dried using UV or hot air. If more than one color is being printed, each color is dried before the next color is applied and the process is repeated.
- Inspection: Many flexographic printing presses are equipped with in-line inspection tools to ensure accurate registration and color. At Eagle, we utilize a top-of-the-line vision inspection system to automatically monitor the print run and flag defects even at very high rates of speed (up to 1600 ft/min). Print is also verified by a quality control technician throughout the run.
Flat Plates vs In-the-round Sleeves
Flexo printing can use either flat photopolymer plates mounted on cylinders or seamless ITR sleeves. Both methods produce high-quality results, but they differ slightly in performance, precision, and cost-efficiency. Whether utilizing flat plates, ITR sleeves, or both, the choice depends on the complexity of the design, print run length, and desired efficiency.
| Flat Plates | In-the-Round (ITR) Sleeves | |
|---|---|---|
| Form | Flat photopolymer sheets mounted to a cylinder | Seamless cylindrical sleeves made from photopolymer or elastomer |
| Cost (approx.) | Lower overall cost per color | Higher initial investment but allows for faster mounting and changeovers |
| Leadtime (approx.) | 1–2 weeks | 6 weeks |
| Continuous printing | Potential for visible seam gap where plate ends meet. | Seamless printing, eliminates potential for breaks in the art. |
| Registration Accuracy | Very good, produces high-quality artwork. | Exceptional, can produce photographic rendering and fine detail. |
| Life expectancy | Properly stored photopolymer plates can typically run more than a half million impressions or more. | ITR sleeves may provide a slightly longer lifespan for high-volume runs. |
| Best for | Applications that require premium quality printing and cost-efficiency. Flat plates are used for most applications. | Artwork requiring very fine detail, continuous printing, or tight registration |
Solvent-Based Inks vs Water-Based Inks
Water-based and solvent-based inks differ primarily in their carrier systems (water versus chemical solvents) which affects both performance and application suitability.
Solvent-based inks offer superior adhesion and durability on a wider range of substrates, making them ideal for high-speed production and challenging applications, including sterile medical and food-grade packaging, when formulated to meet strict regulatory requirements.
Water-based inks may be used in food and medical packaging, however, are slower to dry and less durable than solvent-based inks.
Surface vs Reverse Printing
In flexographic printing, the key difference between surface and reverse printing lies in the side of the substrate where the ink is applied.
Surface printing places the ink directly on the outer layer of the packaging film, making it immediately visible and tactile. This method is often used when the outer surface needs to carry special enhancements (ie spot varnish, soft-touch matte coating) or when lamination is not required.
Reverse printing applies the ink to the underside of a clear film, which is then laminated to another layer. This protects the printed graphics from scuffing, moisture, and chemicals making it ideal for high-end or durable packaging applications where print integrity is critical.
Rewind/Unwind Figures
Designating an unwind orientation determines how the printed film will unroll during converting, filling, and sealing. Unwind direction directly impacts the positioning of graphics, eye marks, zippers, valves, and other functional features relative to the packaging equipment. Incorrect orientation can lead to misaligned artwork, upside-down pouches, or features on the wrong panel which could result in costly rework or waste. By clearly specifying the unwind figure early in the design and prepress process, brands and converters ensure consistent, accurate production and smooth integration with form-fill-seal or pouch-converting machinery.
Flexo vs Gravure vs Digital
Flexographic, gravure, and digital printing are three distinct methods used in packaging, each offering unique advantages depending on the application.
Flexographic printing uses flexible photopolymer plates or in the round (ITR) sleeves to transfer ink onto the substrate in a high-speed, continuous process. It’s ideal for medium to long runs and supports a wide range of artwork and materials, delivering high-quality results with tight registration and fast turnaround.
Gravure printing involves engraving the image directly onto a cylinder and is known for its consistency, color density, and fine detail, especially for very long runs. However, due to higher setup costs, it’s typically only used for extremely high-volume production.
Digital printing uses no plates, printing directly from a digital file. It offers quick setup, versioning flexibility, and low minimum order quantities, making it ideal for short runs, test markets, or personalized packaging. However, digital printing may not match the speed and cost-efficiency of flexo or gravure at scale.
Advantages of Flexographic Printing with Eagle
Partnering with Eagle Flexible Packaging for your flexographic printing needs means access to industry-leading technology, expertise, and print quality tailored to the demands of modern flexible packaging. Our dedicated graphics center is staffed by experienced prepress professionals who ensure every file is fully optimized for flexographic printing and press-ready. While we don’t typically create artwork in-house, our team will guide you through the file preparation and proof approval process to ensure your design is produced exactly as intended. With in-house plate and sleeve production, including state-of-the-art equipment like our Esko Crystal laser and exposure unit for flat plate imaging and our Stork engraver for direct laser engraving (DLE) custom sleeves, we maintain strict quality control from the very beginning.
Our advanced 10-color printing presses, including a top-of-the-line SOMA Optima, deliver exceptional results even for complex artwork (up to 175 LPI). We can produce a range of artwork from crisp line art to detailed photographic renderings, all with tight registration and consistent color accuracy. We offer continuous print capabilities, including full flood coats for opaque color, and spot enhancements like soft-touch matte, gloss varnishes, and clear view windows to elevate your packaging’s visual and tactile appeal. Learn more about our flexographic printing capabilities →
From art file to finished roll, our goal is to provide a seamless experience and deliver printed packaging that exceeds expectations.
