What to Know About Coatings for Inkjet Print

The most commonly used coatings with digital inkjet print are aqueous coatings and UV coatings. 

Like aqueous inks, aqueous coatings are water-based and are prized for their eco-friendly composition and lower cost. Aqueous coatings do not produce a high gloss finishing like their UV counterpart, but they do provide a necessary layer of protection to help preserve your substrate and increase the overall performance and lifespan. 

UV coatings, on the other hand, are typically chosen for their high gloss appearance and enhanced protective qualities. UV coatings can vary thickness depending on how they are applied to the sheet and the type of sheet on which they’re applied. While UV coatings are not 100% waterproof, they are water resistant, a feature that provides strong rub and scratch resistance. 

“UV is most common in more premium printing applications like self-mailers, postcards, brochures, magazines, and packaging,” write Gooding and Schilling. “The downside of UV coatings is that they are substantially more expensive than aqueous and contain higher levels of environmental toxins.” 

What’s more, the method in which aqueous and UV coatings are applied to the substrate can create different finishes and effects. For example, a flood coating evenly covers the entire surface, while a spot coating only covers a very specific area of the paper. While flood coating is used to protect the whole surface of the sheet, spot coating is used primarily for aesthetic purposes to create a more dynamic look. 

“Spot capability is a great partner for inkjet personalization, allowing different aspects to be highlighted on each page,” write Gooding and Schilling. 

The difference between a flooding coating and a spot coating — not to mention a handful of other factors that are discussed in The Designer’s Guide to Inkjet, 3rd Edition — can create a wide range of finishes or effects on the final printed sheet. Depending on the in-house capability of your print partner, some of the finishes you can achieve include: 

• Gloss, which produces a smooth, reflective surface. Gloss can also increase the color depth and detail of your inkjet project, but its highly reflective nature can detract from text legibility and show fingerprints. 

• Matte, which creates a non-reflective surface that makes it easier to read large amounts of text. 

• Satin, which is a finish that combines gloss and matte to produce a fine balance between shine and wear resistance. Satin creates a particularly unique effect where it appears as if the printed sheet has no protective layer at all. 

• Soft touch, which offers a richer matter surface combined with a velvety feel that helps to increase the sheet’s tactile appeal. Soft touch is more resistant to fingerprints, and it also reduces the yellowing of paper over a long period of time. 

“Coatings, along with film, can be used for many other special effects to add value to a printer piece,” write Gooding and Schilling. “You may want to investigate compatibility with more challenging finishes like sandpaper, grit, nonskid, or scratch-off coatings or embellishments.” 

As with most aspects of digital inkjet printing, it’s important to consult with your print provider for a clear understanding of the processes they have at their disposal, and how their processes can help you bring your design to life with an eye toward color and print quality. While the basics of coatings for inkjet print will help you get the conversation started, there’s still much to learn about how coatings can protect, embellish, and enhance your print project.