Metallic ink is a varnish or vehicle containing metallic particles. Common metals used to manufacture metallic ink include copper, aluminum, bronze or zinc. When metallic ink is printed and left to dry, the metallic particles rise to the surface, reflecting light and creating a metallic sheen. Metallic inks create a similar, but less intense, effect than foil stamping because they are applied as paste or liquid ink, versus a thin sheet of metal foil applied directly on top of a substrate. Metallic inks are amazing because they can create the illusion of “high definition print” at a relatively low cost and there are numerous types, including those suited for conventional offset as well as for UV offset capabilities.
It is important to note that metallic inks are opaque, whereas conventional process inks (cyan, magenta, yellow and black) are transparent. Ink technologies, such as MetalFX, rely on the transparent nature of process inks to allow a myriad of colours to be overlaid onto the metallic ink base. This allows one to print as many metallic colours as desired in a single pass of a press.
Design and Production Considerations
Due to the nature of metallic ink, it is important to be aware that rub resistance issues exist, and therefore, advisable to apply a protective coating on top of the surface. There are trade-offs however, because the protective coating may not react well with the metallic surface causing adhesion problems (such as with a film laminate) or the protective coating can lessen the metallic effect.
In order to increase and maximize rub resistance, it is recommended that printers apply metallic ink on coated stock only. The harder and less porous the stock (such as a gloss coated stock) the greater the metallic effect produced. If a customer is interested in printing metallic ink on uncoated or textured stock, the metallic sheen will not be as pronounced because the ink will sink into the pores of the paper. If they are looking to apply metallic ink to an uncoated or textured sheet, the printer may apply two hits of the metallic ink or lay down a thicker film of ink. Alternatively, it may be wise to apply foil stamping (which sits on the surface of the substrate and does not absorb into the pores of the paper) if a full-intensity metallic look is desired. Always test unconventional substrates prior to printing to minimize costly errors.
Additional considerations to take into account when using metallic inks include: the ink is more expensive than traditional offset ink, the ink can take longer to dry, there is increased makeready time and a more thorough cleanup is required to ensure all metallic particles are out of the inking system before moving on to the next job. There can also be more printing problems and special care required, as metallic inks require a different ink/water balance than process inks.
An additional consideration for UV metallic ink specifically, is that a fast drying time reduces the metallic effect. Longer drying metallic inks tend to have a greater metallic lustre because the particles that reflect light have had more time to rise to the surface of the ink.
Designers must communicate with their printer to clarify whether or not the final metallic printed piece will be run through high heat digital presses or home laser printers. If running through a high heat digital press is the intended end use, the metallic ink must be specially formulated to suit this end-use application.
Other important design considerations when using metallic ink include not using it in small areas such as halftone dots. If the dot is smaller than 30% it may simply appear as though it is not printed with metallic ink. Printing reverse type or similar small areas using metallic ink is also not desirable because of the larger particle sizes contained within the ink. Metallic inks are much more effective on large printed areas and so these types of design considerations should be made in the early stages of the project.
Consumers expect more and more from the marketing and promotional material they interact with on a daily basis. MetalFX ink technology provides consumers with more by enhancing product realism (technology, automotive, jewelry, etc.) and visual interest without the added expense of individual metallic spot colours.
MetalFX is a unique printing process whereby a single metallic ink is laid down first (either silver or gold) and then process cyan, magenta, yellow and black (transparent inks) are laid down over top of the base. This provides the opportunity to reproduce over one million metallic colours on a single pass of a five-unit printing press. The possibilities are virtually endless!
MetalFX inks are available for sheetfed offset printing as well as for web offset printing and are available as UV and conventional inks. Designers can now use a whole gamut of metallic colours to maximize their design, without the added expense of individual spot colors, whether for packaging or high-end commercial printing. MetalFX employs proprietary software where users can create sophisticated designs using layers within their files and customize the intensity of each metallic colour.
An added bonus of the MetalFX technology is that the overprinted CMYK acts as a varnish to protect the metallic ink from scuffing and increases the rub resistance.
Other unique effects that can be leveraged using the MetalFX software include LiteFX (light changing metallic colours that creates movement on a page), HoloFX (hidden metallic elements create the illusion of a holograph) and SecurityFX (a combination of LiteFX and HoloFX to create a document that is very difficult to replicate without the original file).
Special training and licensing is required to print MetalFX.
In the end, the most important decisions about whether or not to use metallic inks depend upon the choice of paper, preferred coating application, printing process and the desired effect. Consult with your print specialist to determine the best use for these inks. Shine on!