Founded in 1936, Sappi is a global supplier of dissolving pulp and paper-based solutions. The company has long been focused on renewable wood-fiber products with a strong commitment to sustainability and the circular economy.

Gunnar Sieber, head of Sales, CCK Papers, Sappi Europe, joins L&NW to explore the latest trends in the paper release liner market.

L&NW: How is Sol BCK reshaping the release liner market?

GS: Sappi is spotlighting a paper-based solution that reduces CO₂ emissions, cuts plastic, and keeps performance steady papers. Two years after its first announcement, Sol BCK has become an integral part of Sappi Europe’s release liner portfolio.

Developed at the company’s Alfeld mill in Germany, the paper-based release liner offers a practical alternative to Polyethylene-Coated Kraft (PCK) papers by significantly reducing carbon emissions, lowering material use, and improving recyclability.

L&NW: Sol BCK has now been on the market for two years. What led to its development?

GS: We introduced Sol BCK because many customers wanted a release liner that keeps performance stable but reduces environmental impact. PCK papers use a polyethylene layer to deal with moisture, especially in humid climates. But that coating increases material use, adds cost, and complicates recycling.

We stepped back and asked ourselves how we could keep the required performance while removing the plastic. Sol BCK was the answer. It offers the same essential functionality but with a much lighter carbon footprint. Customers get a  more environmental friendly product that even works better, particularly in regards to heat sensitive further printing of the final laminate.

L&NW: The US market was particularly in focus for this development. Why was this market so important?

GS: In the US, companies widely use PCK as a backing material for self-adhesive films in areas such as vehicle wrapping, indoor and outdoor advertising, shelf labeling, and safety markings. Because these applications often face humid or demanding climatic conditions, converters have historically relied heavily on PE-coated kraft.

But PE comes with a price, in terms of materials, cost, and sustainability. We saw a clear opportunity to offer a paper-based solution that would keep the process stable without the environmental burden. Sol BCK offers customers a way to reduce PE coated papers and cut their carbon footprint by more than half.

The key is a functional coating on the reverse side. The product is not a PE barrier. It is a control layer. It manages how the paper behaves when exposed to humidity instead of sealing everything off. That keeps dimensional stability and flatness steady while maintaining the bond strength converters do expect.

During testing, Sol BCK performed very well, even during heat curing at up to 160 °C. Customers reported that the clay-coated surface also supports smooth siliconization and clean release from adhesives.

L&NW: What impact does this have on CO₂ emissions and material efficiency?

GS: A significant one. Our internal calculation shows Sol BCK can save up to 57% of CO₂ compared with PCK. Removing the PE layer reduces polymer content and allows for lower grammage, which means fewer materials overall. That keeps costs practical for converters while improving recyclability at the same time. It is a combination of environmental and operational benefits. You don’t have to choose between them.

L&NW: Sappi is known for offering a broad release liner portfolio. How does Sol BCK fit into the wider range?

GS: Sol BCK builds on our long-standing release liner expertise. Beside our Sol CCK and Silco Glassine product range, we also offer facestock papers well known under our Parade brand. They are manufactured across several mills in Europe, which helps us offer a stable supply to customers worldwide.

We are an independent supplier in this market, which is also an important point. Some competitors also operate as converters and are active in downstream applications. That can put them in direct competition with their own customers. When customers buy from Sappi, they benefit from a neutral position. We focus on paper – not on converting – so our success is aligned with theirs.

L&NW: Innovation plays an important role in Sappi’s strategy. How does Sol BCK reflect that?

GS: Sol BCK shows how we approach innovation: practical, purposeful, and focussed on what customers actually need. Instead of adding more complexity, we contribute to remove unnecessary plastic and replaced it with a lighter, smarter system. It improves sustainability and keeps performance consistent.

And we continue to build on this momentum. Our work with organizations such as CELAB and our participation in forums like the AWA Global Release Liner Summit show that we are helping shape the future direction of the market.

L&NW: Where do you see demand for Sol BCK going from here?

GS: The interest is clearly growing. As more companies set clear sustainability targets, they are looking closely at every component in their products. This includes release liners. Sol BCK gives them a credible way to reduce carbon emissions and reduce plastic without compromising production stability.

The motivation to use a more environmental friendly release liner is certainly supported by using less raw material (yield advantage) for the same application. Therefore, the stability function of the release liner itself can be offered with a lower substance compared to a PCK.

In addition, there are generally lower costs for a Sol BCK apply compared to the traditional PCK release liner solution. It also now offers commercial coater companies the opportunity to participate in a market where they have been excluded. That’s because only a limited number of PCK manufacturers dominated the market in the past.

For many customers, it is reassuring to know that Sol BCK is now a proven product with two years of market experience. It shows that paper-based release liners can perform at a high level while supporting wider environmental goals. Concluding the Sol BCK product is meant as an addition to the traditional PCK liners in use. This is specifically in application areas where it might be over-engineered.