Sappi has expanded its range of functional packaging papers with a full set of heat-sealable solutions designed for converters, printers and brand owners who want fiber-based alternatives to plastic.

The Seal family – Seal Silk, Seal G Silk, Seal Pure Silk, Seal Natural, Seal Light and Seal Lucent – covers a broad mix of applications and sealing needs while supporting smooth integration into existing packaging lines. Spanning 44–110 gsm and multiple finishes and features (including OBA-free and translucent options), the portfolio is designed to help customers select a grade that fits their pack format, process and visual requirements.

Many companies face pressure from new regulations, including the EU Packaging and Packaging Waste Regulation (PPWR), growing customer expectations and rising demand for recyclable packaging across global markets. At the same time, they need stable sealing results, strong mechanical strength, and materials that run well on existing equipment. Total cost of ownership also plays a role, as paper-based solutions must be competitive with plastic. The Seal portfolio was developed to address these needs and make it easier to move from plastic and composite structures to a mono-material paper solution.

A portfolio built around flexibility and customer needs

Each Seal grade supports different production setups, print methods, visual requirements and sealing strengths. This allows customers to choose a paper that matches their line, pack format or performance needs. Sappi can also support customer-specific requirements such as OBA-free grades or particular surface characteristics.

Seal Silk and Seal G Silk come in 50, 67, 77, 85, 95, 100 and 110 gsm versions. They offer low-to-medium water vapor performance (grade-dependent) and work with flexo and gravure printing. Seal Pure Silk (67 gsm) is OBA-free for customers who prefer a natural look or need certain compliance features. Seal Natural (95 gsm) provides strong sealing strength and hot-tack performance. Seal Light Gloss and Seal Light Natural come in 44 gsm (Natural) and 54 gsm (Gloss) and support flexo and gravure printing. Seal Light Natural is OBA-free. These papers offer a lightweight option for converters who need heat sealing at lower grammages.

Seal Lucent is available in 44 and 54 gsm for applications that benefit from translucency, such as window packs or partial product visibility. 

"We’re seeing brand owners, converters and printers look for reliable ways to change their packaging without adding risk or cost," says Michael Bethge, Sales Director Flexible Packaging. “They need practical choices rather than one fixed solution, along with technical support during the transition. The Seal range reflects that feedback and gives customers a broad set of options."

Reliable performance and strong print results

All Seal papers are designed for consistent sealing and smooth runnability, while their strong mechanical strength supports stable processing and safe transport. The papers also give accurate print results, helping brands reach a clear and defined visual appearance on the shelf. Sappi supports customers during trial runs, including guidance on sealing temperatures, dwell times and machine settings (depending on equipment and application).

Sappi has been developing functional papers for more than 10 years, working closely with customers and OEMs on testing, switching materials and developing new pack formats. This technical support continues through trial runs, where Sappi assists with sealing parameters and converting set-ups.

Packaging applications across primary and secondary use

The Seal range fits both primary and secondary packaging where no complex barrier structures are required and low-to-medium barrier performance is sufficient (grade-dependent). Typical uses include:

• Multi-packs for confectionery, such as twisted products and Neapolitans
• Pillow bags, sachets, stick packs, doypacks and stand-up pouches
• Food and non-food products that need secure sealing without complex barrier structures

The papers are designed as mono-material to be recyclable in the paper waste stream, where suitable collection and sorting systems exist, and are suitable replacements for PE-coated papers and many plastic-based laminates. The broad mix of grammages and finishes makes it easier to replace existing solutions with minimal disruption.

A practical answer to sustainability pressure without added cost

Companies want materials that support sustainability goals while remaining cost-competitive. The Seal portfolio delivers reliable sealing for product protection, strong mechanical properties for runnability and clear print surfaces for brand differentiation. With Sappi’s scale in specialty papers and its technical support, customers gain a stable and efficient path toward recyclable mono-material packaging. For more information and sample orders, visit www.sappi.com.