Many of the products we buy come packaged in a blend of materials. Composites of paper or plastic with other materials can provide lightweight, durable packaging that protects products from breakage, moisture, and leakage. While such composite packaging may do a good job of protecting the products we purchase, it presents a recycling challenge.

Because composites are blends of different types of paper, plastics, metals, or wax, your local recycling program is unlikely to accept them in your curbside recycling bin or the local transfer station. That’s because the materials must first be separated before they can be recycled – and few materials recovery facilities (MRFs) have the equipment to do this. And because it’s often not profitable, there is little incentive.

To be an effective recycler, it’s essential to understand the difference between, for example, a milk jug made of HDPE (plastic #2) and a soy milk carton made from a composite of materials. The milk jug is a single type of plastic, making it easier to recycle. However, cartons are a composite of paper, plastic, and, sometimes, aluminum, so they require special processing. Unless you are sure that your recycling program accepts a type of composite packaging, placing it in your recycling bin can disrupt recycling efficiency.

To start, take a look at some of the products you have at home and identify which ones have composite packaging.

What Composites Are in Your Home?

Many everyday household items you use every day come in composite packaging. Chip bags, cereal bags, plastic and wax-coated papers, candy wrappers, pet food bags, coffee bags, packaging for cleaning and personal care products, dairy and nut milk cartons, and wrapping paper are just a few. Most food packaging is made of composites, including plastic-coated cardboard and bags. Packaging that holds a liquid is likely a composite material.

How To Identify Plastic Composites

Identifying composite plastic packaging materials can be challenging because they are made of multiple layers of different materials. However, there are a few ways to determine if a plastic-like packaging is a composite.

Look for multiple layers: Composite plastic packaging materials typically have two or more layers of different materials, such as plastic films, aluminum foil, or paper. If one side of the packaging is dull and the other is not, it’s a composite material.

Check for a barrier layer: Composite plastic packaging often contains a barrier layer that helps to protect the contents from moisture, oxygen, and other external factors. The barrier layer is usually a thin layer of aluminum or another material, often #3 plastic (PVC), sandwiched between the different layers.

Check for a recycling symbol: Most plastic packaging is marked with a resin identification code that indicates the type of plastic used. Composite plastics sometimes carry a symbol with a number followed by several letters that indicate the different kinds of plastic used in the layers. They may also be marked with the #7 plastic code if they are a mix of two different types of plastic.

Check for stiffness: Plastic film composites are often stiffer than single-layer plastic films. The composite typically will not stretch like ordinary plastic film because it consists of multiple layers bonded to create a stronger and more durable material. If the material does not stretch or has very little elasticity, it’s probably a composite.

Check with the manufacturer: If the container or packaging material does not provide details about its composition, you can contact the manufacturer for information. The manufacturer should be able to provide details about the materials used in the packaging.

New identification technologies: Digital watermarks are now being embedded into packaging to help identify composite materials. High-resolution cameras can detect these postage-stamp-sized codes and contain detailed information about the packaging composition, including whether the materials are food-grade or non-food-grade. 

Real-world examples include:

• Digimarc’s commercial deployment: Digimarc’s GPU-optimized sortation software is now operational at the Hündgen material recovery facility in Germany, where tens of thousands of digitally watermarked items are identified daily
• HolyGrail 2.0 industrial trials: The HolyGrail 2.0 initiative completed successful industrial tests in 2024 on non-food PET bottles, flexible PP and PE packaging, and four different types of rigid packaging across facilities in France and Germany
• Brand implementations: Major companies like PepsiCo, Nestlé, and Mondelēz are actively testing digital watermarks on their packaging
• Greiner Packaging integration: Greiner Packaging demonstrates how digital watermarks can be integrated invisibly into various forms of packaging decoration

Fluorescent markers that glow under specific lighting conditions are also being deployed to enhance material identification during recycling. The Nextloopp project from Nextek has demonstrated high sorting efficiency for fluorescent markers and labels using commercial sorting equipment from TOMRA, specifically designed to differentiate between food, household, and personal care products that current NIR (Near-Infrared) technology cannot distinguish.

How To Identify Composite Paper Packaging

Composite paper packaging materials are also composed of multiple layers, making them more difficult to distinguish from single-layer paper packaging. However, here are a few ways to determine if a paper package is composite:

Look for a plastic coating: Composite paper packaging materials often have a thin layer of plastic coating applied to the paper to protect the contents from moisture and other external factors. The plastic coating can be visible or invisible depending on the package type. Tilting the paper to see if it’s slightly shiny is a good way to know if it has a thin layer of a different material on it if you aren’t sure. Paper is naturally dull, while plastic is not.

Check the weight and stiffness: Composite paper packaging materials are usually heavier and stiffer than single-layer paper packaging. This is because the multiple layers of material are bonded together to create a stronger and more durable package.

Check for a metal layer: Some composite paper packages, such as those used for coffee or soup, may have a thin layer of metal foil sandwiched between the paper and the plastic coating, or it may be on the inside of the package. This metal layer helps to keep the contents hot and prevents them from leaking.

If you are unsure, please check with the manufacturer.

Is Composite Packaging Recyclable?

Putting composite packaging in your recycling bin can contaminate the remaining materials in the bin. For example, the moisture barrier in a chip bag is made with #3 plastic, which contains chlorides that can ruin the reusability of any #1, #2, #4, #5, and #6 plastics mixed with it during the recycling process.

In some cases, composite materials can be separated and recycled. For example, some plastic-coated paper packaging can be recycled by separating the paper and plastic layers and processing them separately. Similarly, some composite plastic packaging can be recycled by separating the different types of plastic used in the layers and processing them individually. Separating these layers is not something people can do at home. Therefore, it adds extra steps to the recycling process.

However, in many cases, composite materials are not recyclable or are difficult to recycle. This is particularly true for packaging that contains multiple materials, such as metalized film or laminated paper. These materials can be challenging to separate and process for recycling, so they often end up in landfills or incinerators. Depending on the item, it may be recycled, but it usually produces lower-quality materials with limited uses.

Recent regulatory developments: The EU’s revised Packaging and Packaging Waste Directive mandates minimum recycling rates of 50% for plastic packaging by 2025, increasing to 55% by 2030. The new EU Packaging and Packaging Waste Regulation (PPWR), adopted in December 2024, requires all packaging to be designed for recyclability by 2030 in an economically viable manner. This regulation will replace the current directive and establish mandatory recyclability requirements for all packaging, as well as stricter reuse and refill targets for industries such as food, beverage, and e-commerce.

Potential Solutions for Composite Packaging

There are two solutions to the problem of composite packaging materials, and both will play a role in reducing the amount of household waste sent to landfills. Companies are developing new recycling technologies and processes that can handle composite materials more effectively. For example, some companies are exploring chemical recycling, which breaks down materials to the molecular level and then uses the resulting molecules to create new products. However, these technologies are still in the early stages of development and have yet to be widely adopted by the industry.

Advanced chemical recycling innovations: Chemical recycling technologies, including pyrolysis and depolymerization, are now being deployed at a commercial scale to process composite materials that cannot be mechanically recycled. These controversial processes reportedly break down plastics into their molecular components to create new materials. ExxonMobil has opened advanced recycling plants in Baytown, Texas, with facilities planned for Rotterdam and Antwerp specifically designed to handle mixed composite plastics.

Mono-material innovations: Manufacturers are developing mono-material packaging with barrier properties for fresh food, where all layers consist of the same type of plastic—typically polyethylene—making recycling much easier while maintaining protective qualities. Examples include TOPPAN’s GL BARRIER product lineup, which combines proprietary barrier technology with polyethylene and polypropylene films, and Mondi’s re/cycle StandUpPouch, made from PP or PE mono-material with a recyclability rating of up to 95% while maintaining high oxygen and moisture barrier properties.

Digital sorting technology: The HolyGrail 2.0 initiative, involving over 160 companies across the packaging value chain, has successfully tested digital watermarking technology at industrial scale. High-resolution cameras can now detect and decode invisible watermarks on packaging, enabling precise sorting of composite materials. Digimarc’s latest GPU-optimized sortation software has reduced the cost of implementing digital watermark detection by nearly 50%, making the technology more accessible to recycling facilities worldwide.

However, manufacturers can make the most significant changes by adopting standardized recyclable packaging materials that are easy to identify, sort, and recycle.

Extended Producer Responsibility (EPR) regulations: EPR laws are expanding globally, with eight U.S. states having ratified EPR legislation for packaging, including California, Colorado, Oregon, Minnesota, Maine, New York, Washington, and Maryland, requiring manufacturers to pay for the collection and recycling of their packaging materials. Washington’s legislation requires producers to ensure 90% curbside recycling access by 2031 and cover 90% of the recycling system’s costs, while Maryland mandates that producers assume 90% of the recycling costs by 2030. More than a dozen other EPR bills are under consideration in state legislatures nationwide. Australia, Korea, and multiple EU countries have set 2025 targets for 100% reusable, recyclable, or compostable packaging.

How You Can Help

By identifying which product packaging is a composite of different materials, you can avoid contaminating your recycling by placing the wrong items in the bin. Other types of beverage cartons, for example, are widely promoted as recyclable, but not all programs can process them. If you’re unsure whether your local recycling program accepts a specific type of composite packaging, please get in touch with them to ask. And if you can’t recycle them locally, you can help by contacting companies whose products you frequently purchase and encouraging them to use packaging that is easily recyclable.

Consumer engagement tools: New digital watermarking technology allows consumers to scan packaging with their smartphones to learn detailed recycling information and proper disposal methods. Some packaging now includes QR codes or apps that provide real-time guidance on local recycling options.

Support policy changes: California’s SB 54 legislation requires 100% of single-use packaging to be recyclable or compostable by 2032, with a 25% reduction in plastic packaging overall. Supporting similar legislation in your area can drive systemic change in packaging design.

Watch for future recycling guides on how to recycle various products made from composite materials.

 Editor’s Note: Originally published on May 8, 2023, this article was substantially updated in June 2025.