Enhanced, shiny packaging stands out on shop shelves. Bart Lauwaert of Grafische Groep Matthys explains why and discusses some techniques for making folding carton packaging shine.
‘Ennoblement creates attention,’ Bart Lauwaert explains. ‘When a consumer walks past a shelf, the light reflects in the shiny packaging and that creates a moving effect that attracts attention. This is evolutionary. That’s why consumers always notice refined packaging. And being seen is the first step to sales.’
Foil printing: Hot- and coldfoil
There are several techniques for finishing folding cartons. One of the most commonly used techniques is foil printing. This involves applying a thin layer of foil, often metallic or holo- graphic, to certain elements on the surface of the packaging using heat and/or pressure. Foil printing can roughly be split into hot- and coldfoil. Although both methods result in impressive decorative effects, they differ considerably in their applications, processes and end results. The choice has to do with print runs, formats, costs, how often a customer wants to change his design and, last but not least, the creative possibilities of each technique,’ says Lauwaert. ‘With hotfoil, you have higher starting costs because of the clichés, which is why you don’t want to change them too often. Coldfoil is easy to change at every production start. Then you look at the creative effects, because they are usually decisive.’
The differences between hotfoil and coldfoil, the possibilities, and the pros and cons.
Bonding by heat
Hotfoil stamping is a common method for applying metallic foil to various materials, including paper, cardboard and plastics: a metal stamp (the cliché) is heated and then pressed against the foil, causing it to adhere to the surface of the substrate. Advantages are that it gives a glossy, eye-catching finish that adds a sense of luxury and exclusivity to the product. Once applied, foil printing is generally resistant to abrasion, making it suitable for packaging. Hotfoil is sometimes less suitable for very large full areas or very fine lines.
Glue ink
Coldfoil, consisting of gold, silver and holographic foils, uses an adhesive ink that is applied to the paper or cardboard in spot via a simple offset plate. Once the adhesive is ‘printed’, the film is applied directly to the surface of the material and adheres where the adhesive is. The printer then prints CMYK inks over it, optionally supplemented with pantone colours. This allows the film to get all possible metallic colours on one printing form, including images. ‘You finish by applying a matt or glossy dispersion or UV varnish,’ says Lauwaert. ‘To enhance the metallic effect or soften the foil look. You can also vary with lacquer.’
Coldfoil makes it possible to reproduce highly detailed designs and fine lines, with countless metallic shades through the printing, making it ideal for complex and sophisticated packaging designs. It can be more cost-effective as it does not require stamps/clichés, but proper consultation is important. Furthermore, the coldfoil process is faster, resulting in a shorter production time, but cannot be applied to all materials.
Foil printing: Digital hotfoil and coldfoil
Besides hot- and coldfoil, there are several digital finishing techniques, such as Scodix and Kurz Steinemann’s DMliner series. I always call this digital hotfoil, because it starts with printed sheets from, say, an HP Indigo printer. Then the sheets go through the unit that applies a lacquer ‘in spot’ and to that lacquer attaches a chosen colour film from the roll. So on the lacquer positions comes the metallic film. This can vary from sheet to sheet, as the lacquer is applied digitally so you can easily vary the design with this technique.’
Instead of a throughput with lacquer, you can also use black toner to which film attaches in a second pass and which is digitally overprinted with colour. I call this digital coldfoil because here, too, you usually apply film first and then print the colour over it.’
One plus one is three
The finishing techniques each have their own unique characteristics. You cannot print an unprinted box made of raw, uncoated kraft liner with coldfoil, but you can with hotfoil. And coldfoil fits better for a combination of various metallic colour effects within one package or printing sheet. Sometimes the techniques are combined, says Lauwaert. Then one plus one makes three. For example, for a luxury perfume or foodstuff. But the budget has to be right for that.’
Grafische Groep Matthys only has cold foil in-house. However, Lauwaert has a broad knowledge of the market and is happy to refer customers to fellow foil experts if necessary. ‘You can forget all techniques, I tell customers. You only need to remember one thing: if you have a shiny question, call us and we will show you the best way.’
Environmentally harmful?
At first glance, applying a thin layer of metal does not match sustainable packaging. But, according to Bart Lauwaert, a 2019 study shows that cold foil printing does not disrupt the recycling process. ‘The glue and metal particles release during recycling with water. They float to the surface and the paper fibres sink, so both elements are separated just fine. The loose particles are skimmed off, dried and then thermally recycled to generate electricity that is used for paper production.’
Text: Harry van Deursen – Verpakkingsmanagement
