Whether you’re looking for a way to make your project stand out or just trying to protect your printed materials, it is important to know there are differences in the type of coating you use. There are four common types of coatings: aqueous, lamination, ultraviolet (UV), and varnish. Each option has strengths and advantages to being used. Make sure you understand the coating you are using. This not only helps smooth the process along, but it also can add creative dimension to your project.
As the name states, aqueous is a water based coating. It is clear and fast drying. Aqueous coating can provide either a high gloss or matte finish and can help improve durability. This coating is often used on business cards due to its ability to resist fingerprints and smudges. In most cases, aqueous coatings tend to be used on the entire project rather than in spot coating. This type of coating can be applied either after the printed material is finished on the press or during the printing process. The advantages to using an aqueous coating are: provides better clarity; fast drying; unlike some coating options, aqueous does not turn yellow with age; it has a higher rub resistance; it is more environmentally friendly than other coating options; and the glossier finish can be used on a variety of paper grades. The disadvantage to using aqueous coating is it is vulnerable to chemical burns, although it generally only happens in a small number of projects.
There are two main types of laminates: liquid based and film based. A film based laminate is put on by placing a clear plastic film overtop of the paper being laminated, while a liquid lamination is coated onto the paper and dries like a varnish. As with other coatings, you can have either a gloss or matte finish. The advantage to using lamination is it protects your printed materials even from water. Lamination also provides a washable finish. However, one of the biggest disadvantages to lamination is it generally is more expensive than other coating options.
Ultraviolet coating is applied as a liquid and then dried (hardened) using an ultraviolet light. This type of coating offers better protection than both varnish and aqueous coating options, and it has a variety of finish options including: satin, gloss, matte, and more. UV coating can be applied in one of two methods: either offline by using either a converter or finisher, or it can be applied during the printing process. The advantages to UV coating are: provides a higher gloss than any other coating option; better clarity; and has a higher resistance to rubbing and abrasions. The disadvantages to using UV coating are: can cause certain colors to change in appearance; is vulnerable to chemical burns; and can have a slight odor depending upon the type of UV coating used.
The best way to describe varnish is as a colorless ink. Unlike some of the other coating options, varnishes require the use of an offset spray powder before the varnish is dried. This helps prevent the printed materials from sticking together. Although varnish coating offers protection from dirt and smearing, it offers the lowest degree of protection out of the four coating options. This type of coating must also be handled very carefully. Otherwise, it can release harmful compounds. It is available in gloss, satin, and matte finishes; either with or without the use of color tinting. However, a gloss varnish tends to reflect more light than other gloss finishes. It also adds to the sharpness of the image. Matte and satin varnish can actually increase the readability by diffusing the additional lighting and reducing the glare. One of the biggest advantages to varnish is price, because it is the cheapest coating option available. Unfortunately, the disadvantage to using varnish is over time it can yellow in appearance.
Before deciding on a type of coating for your project, think about what you are trying to achieve. For instance, if you’re creating menus for your restaurant, you probably want to use a laminate to allow the ability to wash the final product when needed. Other times, the coating choice can depend on the final cost of the printing project. Think about the disadvantages as well as the benefits to your coating choice, especially if environmentally friendly options are a factor.
1 – Cover Image courtesy of www.blog.lexjet.com