What Is Flexographic Printing for Custom Packaging?

About 60% of the world’s packaging uses flexographic printing. It’s flexible, efficient and fast, and it tends to be less expensive than other forms of printing. Packaging is more than a way to get products safely from Point A to B. It’s part of a company’s brand story, and the receiving and unboxing experience is an important aspect of a shareable customer experience. With the global custom packaging industry expected to grow at a CAGR of  5.70% from 2024 to 2034, flexo printing has a bright future ahead.

Let’s find out what flexographic printing is, how it’s used to create memorable custom boxes and how you can use it to your advantage.

What Is Flexographic Printing? 

Flexo printing uses flexible plates and quick-drying inks to print high-quality designs directly onto packaging materials. It was created by an English paper bag printing company in the 19th century. In the early 20th century, a way was found to chemically fix the ink and stop it from bleeding when wet.

Next came advances in ink transfer and consistency with the first mechanically engraved metering roll. By midcentury, the flexographic printing process was applied to many different types of packaging, from corrugated boxes to grocery bags.

With the technical revolution in the late 20th century, photopolymer plates were stronger and easier to produce. Laser-engraved ceramic anilox rollers and UV-curable inks were born. Ink distribution was more consistent, precise and faster-drying. By 2000, with digital precision in plate making and improvements in press speed and automation, flexo printing had become the dominant form of printing in the packaging industry.

The Flexographic Printing Process for Custom Boxes

Let’s look at how flexographic printed boxes are created step by step:

Plate preparation: Once a packaging design has been created and tailored to flexographic printing specifications, flexible printing plates are made from photopolymer or rubber materials, and each plate is etched with the desired design or artwork. Each color will have a separate printing plate, so the design is separated by color. The plate material is exposed to UV light through a film positive. This hardens the image areas and leaves the non-image areas soft and removable. A raised relief image remains on the plate once the soft, non-image areas have been washed. 
Plate mounting: The prepared plates are mounted onto rotating printing cylinders within the press.
Ink application: Anilox rollers pick up a precise amount of ink and transfer it evenly onto the raised surfaces of the printing plates.
Substrate feeding: The packaging material, like corrugated board, is fed through the press, ready to receive the printed image.
Image transfer: As the base material onto which images or text are printed passes through, the inked plates press the design directly onto the material, creating the printed image.
Drying/curing: The printed boxes move through a drying or curing system to set the ink quickly and prevent smudging. This system commonly uses heat or UV light, depending on the ink type. 
Finishing touches: After printing and drying, the material is cut, folded and glued as needed to form the final custom boxes, ready to wow your customers.

Benefits of Flexographic Printing for Custom Packaging

Flexographic printing advantages, like cost efficiency, high-speed production and consistent results, make this technique a popular choice for high-volume jobs. There are many reasons to choose rotary printing for custom packaging:

Versatility across different packaging materials: While flexographic printing on cardboard is common, flexo printing can be used on many different products, such as self-adhesive labels, food packaging, shopping and retail bags, envelopes and even flexible plastic and wallpaper.
High-speed production capabilities for efficient large runs: A flexographic press can run at speeds exceeding 3,000 feet per minute without compromising color and clarity.
Cost-effectiveness for medium to large print runs: Custom plates are created once during the initial setup, and the cost is spread across thousands or millions of printed items.
Ability to print directly on uncoated and rough surfaces: Flexo printing can handle coated papers, custom corrugated boxes and other unusual substrates.
Environmental benefits through water-based ink options: Water-based inks minimize harmful emissions and reduce the overall carbon footprint compared to traditional solvent-based inks. They have a lower volatile organic compound (VOC) content, are safer to dispose of and reduce water pollution. 
Durability and resistance of printed images: Using carefully selected inks and finishes, with options for water and weather resistance, flexographic printed images can withstand handling, shipping and environmental exposure. 

Limitations of Flexographic Printing

While this printing technique is popular with businesses looking to increase the impact and appeal of their products at every consumer touchpoint, there are some limitations to note:

Initial setup costs for plates and equipment: Designing and setting up the plates involves an investment, which is why flexo printing is not recommended for short print runs.
Limitations in reproducing fine details and gradients: Achieving fine detail and smooth color gradients can be challenging, making this method less than ideal for complex designs with multiple colors or high-resolution images.
Color matching challenges compared to other printing methods: Variables like ink viscosity and plate wear can make maintaining consistent color throughout a long print run a challenge. 
Minimum order quantities may be higher than digital alternatives: Flexographic printing needs custom plates and setup for each design. This makes it more cost-effective for larger production runs. As a result, printers often set higher minimum order quantities compared to digital printing, which can print small batches without special plates or extensive setups.
“Flexo bounce” and other quality issues: Flexo bounce is a print defect that can happen during the printing process. Vibrations or uneven pressure can cause repeating patterns, streaks or blurry areas, especially on large, solid-color areas or at high speeds. Other quality issues can include color layers that aren’t perfectly aligned or less precise detail compared to digital or lithographic printing, particularly on very intricate designs.

Choosing Between Flexo and Other Printing Methods

The three types of printing methods you’ll choose from are flexographic, lithographic and digital printing. Here are some of the reasons to choose one over the other.

Whether you choose flexographic label printing for different types of boxes or shopping and retail bags, flexo printing is best for:

Providing a cost-effective option for bulk print runs. 
A speedy setup when facing a tight deadline. 
Simple designs and a limited color palette. 

Lithographic printing is best for creating magazine-quality print and is ideal for:

Many different types of materials, including magazines and product packaging.
Producing quick, high-quality prints of repeat items.
Delivering clear, high-resolution, complex graphics. 
Using less ink than with flexo printing, but it can require additional laminating runs and has limited options for unusual box sizes.

Digital printing reproduces electronic images onto different materials. It’s best for:

Creating hyperrealistic, vibrant, high-resolution images or photos. 
Making revisions to the design easier and for highly customizable prints. 
Providing flexibility for short runs. 
Removing the need for extra formatting materials and prepressing, but it can be more costly for high runs.

Getting Started With Flexo Printing for Your Custom Packaging

Understanding flexographic printing and how custom-printed boxes can benefit your business will help you decide which method is best for you. Still not sure? At Bolt Boxes, we know your packaging requirements are unique, and we’ve been helping our customers create personalized packaging for almost 60 years. We offer flexographic, lithographic and digital printing services on a variety of materials.

Build your custom box or contact our team to learn more about our capabilities.