When they were first introduced, it's no exaggeration to say that coated white top kraftliners sparked a revolution in the world of corrugated paperboard and packaging. While its main job has always been to protect what's inside, modern packaging plays another equally important role – showcasing a brand's image and acting as an eye-catching sales tool. And this is where coated liners really come into their own.

"Back in the 70s, corrugated board was basically used to make big brown boxes to transport things in, because they were robust and sturdy," says Pertti Kaasalainen, former Technical Customer Service Manager at Metsä Board.

Kaasalainen, or "Mr Corrugated" as he was known to his clients, saw first-hand how visual appeal became as important as robustness in the packaging world.

More and more brand owners started to look for materials that would allow them to create glossy, attractive designs with excellent printing results, which is exactly what coated kraftliner delivers.

Pertti Kaasalainen

Consumer appeal was the main driving force behind the adoption of coated kraftliners, but they also brought another change to the market – notable opportunities for saving heat and energy in the corrugating process. Coated liners can be run cooler and minimise preheating. This "less is more" philosophy plays a crucial part in reaping the benefits of coated liners. and it represented new thinking at the time. It still does.

"There's always a tendency when things don't go right to add more rather than take things away – more steam, more heat, more glue – but with coated liners, the opposite is what's needed," says Kaasalainen.

The introduction of coated liners heralded a change in the industry's philosophy.

"The liner produced at Kemi was the first of its kind on the market. In my opinion, it was the start of a worldwide revolution in corrugating," Kaasalainen says.

"With these liners, moving from a hotter to a colder setup means producers get the best results from the materials they're running and improve their energy efficiency at the same time. It's a true win-win," he concludes.

Ongoing investments in the Kemi mill will eventually help it to achieve completely fossil free operations and energy self-sufficiency, setting a new benchmark in the industry and driving further improvements in sustainability.