Three Real Boundaries of Packaging "Bio-Based" Claims: Content Percentage / ISCC PLUS / Brand-Defined Criteria — The First Three Questions a Printer Should Ask for a Bio-Based Labeling Order

In October 2026, a new personal-care brand customer approached us with a photograph of a competitor’s package.

There was a small icon on the photograph with a line of text beside it. We examined it for a long time without being able to read it clearly. The customer said it was the competitor’s “bio-based label” and asked, “Can we make something similar? Part of our material is actually bio-based.”

We asked, “Which part, and what percentage?”

The customer replied, “The ink is plant-based. The paper is FSC certified. As for the box as a whole... it contains bio-based components in any case.”

This answer exposed the core issue directly: Between “contains bio-based components” and “this is bio-based packaging” are three conditions that must be clearly established.

We spent more than an hour explaining the issue to the customer. They eventually decided to defer printing the label until the material list and content calculation had been completed. This was the correct decision because, in many markets, an unsupported environmental voluntary claim printed on packaging may become a point of challenge.

The First Boundary: Three Methods for Calculating Content Percentage

The first boundary concerns how the “content percentage” is calculated. In practice, there are at least three methods, and choosing the wrong one produces an incorrect figure.

Method 1: Calculation by weight (mass balance). This is the most common and easiest to explain: what proportion of the package’s total weight comes from bio-based sources? The formula is: the mass of bio-based materials ÷ the total mass of the package. This method is intuitive, easy for customers and consumers to understand, and is also the approach most commonly used by certification bodies.

Method 2: Calculation by carbon content (carbon balance). This method is more common in the chemical and materials industries. It calculates the proportion of bio-derived carbon in total carbon. Its advantage is that it reflects the sourcing attributes of the material itself without being affected by non-carbon components such as fillers and moisture. Its disadvantage is that consumers cannot understand it. A statement such as “62% carbon content” printed on a package would leave most consumers without a clear understanding of its meaning.

Method 3: Calculation by “which portion.” This is the most confusing approach. The same batch of packaging may support three statements simultaneously: “30% of the package is bio-based material” (calculated for the entire package), “the ink is 100% plant-based” (calculated for a single component), and “the film layer is bio-based” (calculated for a specific layer). All three statements may be true, but printing them on packaging without qualifiers is misleading.

Our factory’s practice is to require a qualifying explanation whenever any percentage is printed. Here are three examples:

“30% of the total package weight comes from bio-based materials” (mass balance with clearly defined scope).

“The printing ink uses vegetable-based oil” (describes a component without providing a percentage).

“The inner film layer is a PLA-based material” (describes a specific layer without implying an overall claim).

A customer asked, “Can’t we simply print ‘30% bio-based’? That is what the competitor does.”

We replied, “You need to specify that it is calculated by weight and applies to the entire package. Without even one qualifier, you will be asked to revise it during review.”

The Second Boundary: What ISCC PLUS Does and Does Not Certify

The second boundary concerns certification systems, and misunderstandings here are particularly widespread.

First, ISCC PLUS is a supply-chain certification system for biomass and sustainable raw materials. Its core function is to demonstrate that raw materials within the supply chain originate from sustainable sources and that this information can be traced back through the chain. In packaging, it is typically used when packaging contains bio-based plastics, such as PE made from bio-based ethylene or bio-based PET, and the customer wants third-party support for the “bio-based” claim.

Then, what does ISCC PLUS not certify?

It does not certify that “this package is environmentally friendly.” It certifies raw-material sourcing and traceability, not the package’s overall environmental performance. A package may be ISCC PLUS certified while being extremely difficult to recycle and containing substantial barrier composite layers.

It does not certify that “this package is sustainable.” “Sustainable” is a much broader judgment than “traceable” and involves life cycle, resource efficiency, social impact, and other factors.

It does not certify a specific finished product. Certification generally applies to raw materials or a particular production stage rather than to the printed box in your hands.

There is also a critical practical point: Certification is chain-based rather than point-based. If a customer says, “Our film has ISCC PLUS certification,” the printer must ask which part of the chain it covers. Is it the upstream resin supplier’s certificate, or the certificate issued after conversion by a converter? Is the intermediate conversion stage included in the certificate chain? If this is not clarified, the mark may be printed on the package, but the chain will be broken when the finished package is traced through to the end customer.

The customer said, “Our film supplier has an ISCC PLUS certificate. I will send it to you.”

We replied, “Does this certificate cover the resin or our finished film? Was there an intermediate conversion? Can the certified entity name and batch number on the certificate be matched to this shipment?”

After these three questions, the customer would generally know whether the certificate could be used. The customer said, “I thought having a certificate was enough.”

The Third Boundary: Brand-Defined Criteria Are the Most Dangerous

The third boundary, and the one requiring the greatest caution from printers, concerns environmental wording defined by brands themselves.

There are many examples: “plant-based ink,” “eco-friendly ink,” “biodegradable packaging,” “green packaging,” “low-carbon packaging,” and “plastic-free packaging.”

These claims have three levels of issues.

First, some wording has a precise definition under specific regulations and cannot be used freely. Terms such as “biodegradable,” “compostable,” and “recyclable” have corresponding technical standards and labeling rules in most major markets. For example, the EU compostable-labeling requirements refer to EN 13432, while recycling labels have dedicated graphic specifications. Printing these terms without qualification amounts to declaring that the product complies with the relevant standard when it may not have passed the required testing. This is a matter of legal risk, not merely wording.

Second, some wording has no statutory standard and therefore no statutory meaning. Terms such as “eco-friendly ink,” “plant-based packaging,” and “green design” have no corresponding technical definitions or assessment methods in most regulatory systems. They do not constitute regulated claims, so printing them does not directly violate the law. For precisely that reason, however, they fall entirely within the ethical scope of voluntary claims: once printed, the printer has participated in the statement.

The customer asked, “Our ink is plant-based. Is there any problem with printing that?”

We replied, “Technically, no. But I recommend considering two matters. First, whether this wording could be interpreted as a compliance claim in your market. Second, whether you have supporting materials that explain precisely what ‘plant-based ink’ means if a competitor or consumer questions it. If the purpose is simply to tell consumers that this ink is not solvent-based ink, a more specific formulation is safer.”

Our factory’s actual practice is: Whenever we cannot provide technical support for an environmental claim, we add a separate note on the sample approval sheet and have the customer sign it. This is not a refusal; it creates a documented record. By signing, the customer acknowledges that they understand the meaning and risk boundary of the statement.

Third, “overall” statements are the most complicated. A sentence such as “this box is biodegradable” or “our packaging is environmentally friendly” describes the whole package, but its overall environmental performance is precisely what cannot be determined by any single material. Paper may be biodegradable while the film is not, and ink may be biodegradable while the adhesive contains plasticizers. Printing “biodegradable” on a box makes a commitment covering the entire structure.

The First Three Questions to Ask for a Bio-Based Labeling Order

When these three boundaries are brought together, they become three practical questions.

First: the calculation basis for bio-based content. Specifically: calculated by weight or by carbon? Does it cover the entire package or a specific layer? What are the numerator and denominator? Our practice is to ask the customer for a material list containing the name, supplier, grade, weight percentage, and bio-based sourcing status of every material. We then calculate the figure using the criteria confirmed by the customer and include the calculation process in the delivery documentation. If the customer cannot provide a material list, the figure should not appear on the package.

The customer asked, “Is there an approximate figure?”

We replied, “There is no such thing as an approximate figure. A figure printed on packaging must withstand scrutiny. Either you provide the material list so we can calculate it, or you remove the statement.”

Second: who issues the figure and under what certification. There are three possibilities: the printer calculates it from the customer’s material list, making the printer the data compiler while responsibility for the accuracy of the customer-confirmed list remains with the customer; a third-party certification body issues it, making the printer the executor; or the customer self-declares it, in which case the printer must document that the figure came from the customer. All three approaches are acceptable, but the chosen method must be clearly recorded in the documentation.

Third: where the label appears and which standard it follows. This determines the form of the label. Marks belonging to third-party certification systems, such as ISCC PLUS, certain FSC labels, the EU compostable mark, and China Environmental Label, have specified artwork, colors, dimensions, and placement and must not be replaced with a self-designed icon. Custom wording that is not part of any system should be presented mainly as text, with consistent use across all package panels. If “plant-based” appears on the front but not the back, consumers may find the packaging inconsistent.

There is another practical reminder: Labels have minimum-size and contrast requirements, particularly when certification support is required. If the icon is too small or the color contrast is insufficient, the certification body or platform reviewer may determine that it does not comply with the usage rules. This is directly controllable on the printing side, so the printer must confirm size requirements before ordering rather than after printing.

One Sentence for Our Customers

Regarding bio-based claims, the most important message we want to convey to customers is: “What this label really addresses is not how environmentally friendly your packaging is, but where your raw materials come from and whether they can be traced.”

A bio-based labeling system answers questions of sourcing rather than environmental performance. Customers often expect it to function as an environmental credential, but its function is much narrower than that. That narrow scope is precisely what gives it credibility.

We therefore recommend that customers first clarify who the statement is intended to address and what problem it is intended to solve. If it is intended for procurement or compliance teams to demonstrate supply-chain traceability, proceed with certification and use the label according to the applicable rules. If it is intended for consumers to communicate material information, use specific and verifiable wording rather than broad claims. If the objective is to use an environmental claim as a marketing credential without supporting materials, the answer lies not with the printer, but with the materials and supply chain.

We also often tell customers: “Every environmental term on packaging is a commitment that can be challenged. Before writing it, ask yourself three questions: Where did this figure come from? Who stands behind it? If it is questioned, what evidence can I provide?”

Further Reading

• Four Packaging Environmental Certifications: FSC / CFCC / PEFC / China Environmental Label — The artwork and usage rules for these labels are far more mature than those for bio-based labels.
• Four Certification Standards for Biodegradable Packaging: ASTM D6400 / EN 13432 / GB/T 19277 / HJ/T 209 — The specific thresholds for using “biodegradable” on packaging.
• Recycled Paper vs. Virgin Paper for Packaging: A Real Cost Comparison Across 3 Brand Positioning Strategies — Recycled paper has another set of claims beyond “bio-based.”
• 3 Common Printing Errors in the GB 18455 Recycling Triangle Label: One Incorrect Number Can Prevent Customs Clearance — The most common labeling failures encountered on the printing side.