Varnish – as it is commercially called – can make a big difference to printed paper and packaging. Similar to ink, it is applied on the printing press and helps enhance the visual appearance of the print or packaging.
Types of varnish
Gloss varnish: Used to achieve a smooth surface, gloss can be applied over the full surface area or in specific areas. It creates a special as well as a contrasting effect, while increasing the depth of color and detail. But it also results in a reflective surface that may interfere with the readability of text.
Matte varnish: Matte varnish creates a smooth surface and a soft, subtle appearance. Being a non-reflective surface, it makes text easy to read. If you’re looking for a dynamic effect, you’re better off sticking to gloss. However, a number of effects are possible with this type of coating. Also, like spot UV coating, matte varnish can be spot applied with a high level of precision.
Satin varnish: A combination of matte and gloss varnishes, satin varnish strikes a balance between medium shine and reliable scuff resistance. It is quite discreet and doesn’t draw attention to the fact that some kind of coating has been applied to protect the printed paper/packaging.
Strike-through matte varnish: Strike through refers to a technique in which both matte & gloss varnish are coated on the same printed area. A matte varnish is first applied to all areas of a coated sheet with the exception of those where a glossy effect is needed.
A high gloss AQ coating coating is then flooded over the entire sheet to allow the matte varnish ‘strike-through’ to the surface and leaving the glossy areas shine. The intention is to create a visual distinction between different areas of the press sheet.
Advantages and Disadvantages of varnish
Varnish increases the perceived quality of the product. It is also an inexpensive and user-friendly process that can be easily applied to such as adding spot finishing or additional processes across the entire sheet. It has the ability to be manipulated to get the desired end result.
However, it offers a lower degree of protection compared to aqueous coating and UV coating. They are also susceptible to yellowing over time. Varnishes are also not particularly eco-friendly, and must be handled carefully to prevent the release of toxic compounds into the atmosphere.
There isn’t a single process, rather different methods used to achieve different results. For instance, in wet trapping the varnish is laid in-line over wet ink for thorough registration. In contrast, dry trapping involves drying the ink and putting it through the press twice in order to print the varnish.