Printing Methods: Flexography vs. Offset vs. Digital
There are many different printing processes that happen in manufacturing today. Here, we will highlight the main three processes used in packaging, including their advantages, disadvantages, and which materials work better with which methods.
Flexography is a printing process that uses a flexible printing plate to print on various materials, like paperboard, corrugated cardboard, metallic films, and plastic. It is often used for printing on food packaging, as it works well on non-porous surfaces (food packaging is non-porous to keep contents fresh). The main steps in the flexography printing process are: art preparation, plate-making, mounting, printing and finishing.
Flexography printing works on both coated and uncoated surfaces. There are also a wide variety of inks to choose from, for example water-based inks, UV curable inks, and solvent inks. Ink drying times are also very fast, which leads to lower costs and more efficiency compared to other methods. Flexography printing is flexible and durable—it can last for hundreds of thousands of impressions.
Flexography printing cannot do detailed or complex jobs that methods like offset printing can. Each color needs a separate plate, and the cost of plates is high. Because of plates and set up time, this process is also not ideal for short runs.
The offset printing process (offset lithography) transfers ink from a plate to a rubber roller and then to the material surface. There are two main offset processes. Web-fed is when rolls of paper are fed into the machine and the paper is cut afterwards. This is ideal for creating large quantities in a short period of time. Sheet-fed process feeds pre-cut sheets of paper individually into the machine and produces smaller quantities. It is still considered to be fast, though not as fast as web-fed.
The offset process produces high image quality with excellent brightness and color depth, and can use the Pantone matching color system for high color accuracy. It is also quite cost efficient for longer runs—the higher the quantity, the cheaper it becomes. Offset also allows for a variety of coating options, such as matte, gloss, soft touch and aqueous coating. To learn about these in detail, read this article.
It’s too expensive to set up for short runs, which is why most companies will have quantity minimums on this printing process. It is not as fast as flexography printing, so is not as ideal for mass quantities of simple printing jobs.
Digital printing is very similar to how an office or home laser or inkjet printer works. The digital printer accepts digital document data and outputs the information as graphics and text onto the desired material. It uses toner and liquid ink, and does not need plates like other traditional methods.
Because of the simplicity of set up, digital printing allows for fast turnaround times, especially for low volume orders. This makes smaller orders more affordable. It is also ideal for simple designs, often found in e-commerce packaging. Digital is also great for creating quick samples, especially for prototyping custom jobs.
Digital Disadvantages Digital printing lacks the image quality and color accuracy compared to offset, as well as the material flexibility. There are also paper size and substrate limitations compared to traditional methods.
Which process for which packaging material?
Stiff packaging material usually needs the offset printing process, as you would want the quality of the print to match the quality of box.
Corrugated material can be used in any of the printing types—it depends on what your design requires. For example, if you want a large volume, spot printing or foil stamping, offset may be the best choice for you.
Paperboard packaging typically uses offset printing, especially for consumer retail packaging. This is because of the quality image offset can deliver on small designs.
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