Custom printing services comprise multiple technologies, from letterpress to gravure, from digital to offset, from thermography to engraving to flexography. Whether you want to print custom labels to affix to your wine bottles or print custom decals to advertise your business, a printing technology exists that is ideally suited to your needs. Among these, one form of business printing with which you may not be familiar, but which you hold in your hand every time you pick up a carton of milk, is flexography.
What Is Flexography, and How Does It Differ from Offset Printing?
Flexography is a relief printing process that uses plates made out of rubber (wrapped around a cylinder on a printing press) to print text, halftones, etc., on paper or another substrate. The key word here is “relief.” Flexography (also referred to as “flexo”) uses plates on which the image area is raised and the non-image area is recessed. This is not unlike letterpress or even typewriter keys.
When you ink the raised portion of the rubber plate, it will print the text, photos, or art, but the recessed non-imaging areas, which receive no ink, will not print. In contrast, offset printing uses a flat printing plate and relies on the natural separation of oil and water (oily ink and water, in this case) to distinguish between printing and non-printing areas. Ink is attracted to the image areas (which are receptive to oil), while non-image areas repel the oily ink and attract water (and therefore do not print).
Flexo Is Ideal for Product Packaging.
The boxes of milk and prepared food you see in grocery stores more than likely were printed via flexography. So were the plastic bags you fill with oranges and apples. Or the fancy shopping bags and wrapping paper you use on holidays. Metallic foil, acetate, even corrugated boxes and brown kraft paper are often used as substrates for flexo printing services. Another item often printed this way is self-adhesive (Crack’n-Peel) labels. Some newspapers even print via flexography rather than offset.
Flexo inks are water-based rather than oil-based (unlike offset inks). They are also not as thick as offset inks, and hence they dry faster (which allows for faster production operations and therefore lower costs).
How Do You Know When a Printed Product Was Produced Via Flexography?
1. Offset lithography will print finer type and halftone dots than flexography, so look for crisp (or slightly fuzzy) edges with your loupe to determine the printing technology. Dot gain is also higher on a flexo press than an offset press.
2. From one press sheet to another you will also see more consistent output with offset than with flexo printing.
3. Look at the area screens and halftones. Flexographic minimum (highlight) dots will not be lighter than 2-3 percent. In other words, an offset press can reproduce a lighter halftone dot than a flexo press can.
4. Finally, using a loupe, look for halos around the type. The outside edges of the type letterforms may be denser (or ever so slightly raised) on a flexo printed sheet than an offset printed sheet. It may look as though someone had traced around areas of ink (type and art) with the same color of ink.
The good news is that this custom printing process has been improving, but if you’re trying to determine the printing method used, these tests will help. Plus, you can factor in the substrate (such as the non-porous food packaging materials) when determining how a product was printed.
Choose flexography for printing custom decals, custom labels, wrapping paper, or flexible packaging for such items as food. In your research, look for printing companies that specialize in this process, since most commercial business printing vendors do not have this capability.
This entry was posted
on Thursday, May 19th, 2011 at 3:37 pm and is filed under Printing.
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