#packagingscience

The best production systems remove uncertainty from packaging. Measuring, controlling, and repeating processes ensures reliable results. Consistency is the foundation of scalable beverage production.

By Diana Mocanu, PRINTCO SRL, Romania

Adhesive labels might seem simple. After all, how hard could it be to stick a label on a product?

But once you’ve spent a few years in the printing and packaging world—like we have at PRINTCO SRL in Romania—you quickly realize that getting adhesive labels “right” involves a surprising amount of science. From the materials used, to the surface the label’s applied to, even the environmental conditions in which the label is applied and stored… every step can influence the outcome.

And when labels fail—when they peel, bubble, fade, or slip—it’s not just a small annoyance. It affects brand perception, regulatory compliance, shelf appeal, and customer trust.

So, let’s peel back the surface (pun intended) and talk about the science behind adhesive labels—and what you need to know to make sure yours do their job beautifully.

Adhesion Is Chemistry, Not Guesswork

At the heart of it, an adhesive label relies on two things: the face material (what the label is made of) and the adhesive (the sticky part that makes it stay put). Sounds straightforward—but it’s a balance of chemistry and physics.

There are three primary adhesive types:

1. Permanent Adhesives These are designed to stay. Once applied, they form a bond that’s difficult to break without damaging the label or the surface. Most consumer goods—bottles, food jars, shipping labels—use permanent adhesives.

2. Removable Adhesives These create a bond that’s strong but reversible. They’re ideal when labels need to be removed cleanly, like on promotional stickers or re-usable containers.

3. Repositionable Adhesives A bit of a hybrid—these allow for initial adjustment and reapplication before eventually setting into a more permanent bond.

Choosing the wrong one for your use case can lead to disaster. A removable adhesive on a juice bottle in a humid supermarket? That label will slide off faster than you can say “quality control.”

Surface Matters More Than You Think

One of the most misunderstood factors is the substrate—the surface the label is being applied to.

Is it glass? Cardboard? Plastic? Is the surface smooth or textured? Clean or coated with oil?

A label that works perfectly on a matte cardboard box might behave very differently on a slick PET bottle. And while it might sound tedious, testing adhesion on the actual surface, under real conditions, is a must.

At PRINTCO SRL, we’ve had clients bring us beautifully designed labels that failed miserably in practice because no one tested how they adhered to curved, moist, or low-energy plastic surfaces. In one case, a beverage brand’s labels kept bubbling during transit—not because of a printing error, but because the container had a very slight condensation issue. The solution? We switched to a stronger, moisture-resistant adhesive with slightly higher tack. Problem solved.

Environmental Conditions Can Ruin Everything

Temperature, humidity, and even time of day during application play a huge role.

Most adhesives are pressure-sensitive, meaning they bond better when a certain amount of pressure is applied during labeling. But if a label is applied in a cold warehouse? Adhesion can be weak. If it’s too hot, the adhesive can become too soft, causing slippage or mess.

Also, over time, labels can become brittle if exposed to UV light or fade if the inks aren’t UV-resistant. That’s why we always ask clients about storage and distribution conditions—because the label has to survive the journey, not just the print line.

Face Stock: More Than Just Looks

The face stock—the material on which the label is printed—is just as important as the adhesive.

Paper face stocks are cost-effective and great for dry, indoor environments. Filmic face stocks (like polypropylene or polyethylene) are better for durability, flexibility, and water resistance.

Need a label to wrap around a shampoo bottle? Go filmic. Want something rustic for a small-batch jam? Paper might do the trick. But even that decision should be made with longevity and end-use in mind.

Liner Materials and Application Speeds

Here’s a detail that often gets ignored: the liner—the backing paper or film that carries the label before application.

Some liners work better in high-speed labeling machines, while others might tear or slip. A poorly matched liner can stall production or jam the machine, costing time and money.

If you're printing in large runs or using automated application, the liner choice matters. It’s not something that gets printed on, but it plays a silent, essential role.

Testing and QA: The Unsung Hero

This is the unglamorous part—test runs, peel strength testing, aging simulations, and accelerated exposure testing. But without these, you’re essentially gambling with how your product will perform out in the world.

At PRINTCO SRL, we often run small batch simulations in our workshop, mimicking extreme conditions to see how a label behaves. It’s not about being overly cautious—it’s about being realistic. A label that looks good in the lab but fails in real-life logistics adds cost, rework, and reputational risk.

Why It Matters

You might wonder—does the customer really notice this level of detail?

Here’s what I believe: customers might not consciously notice a perfect label. But they will absolutely notice a flawed one. A peeling corner, a bubbling surface, a faded logo—all send subtle messages of neglect, even if your product is top-tier.

Adhesive labels are silent brand ambassadors. If they do their job right, they quietly affirm your product’s quality. If they fail, they shout.

Final Thoughts

The science of labels isn’t just about chemistry—it’s about care. It’s about aligning form and function. And it’s about collaboration between designers, print specialists, engineers, and brand owners.

As PRINTCO SRL prepares to attend the 2025 Go Global Awards in London this November—where we’re honored to be nominated—we’re reflecting on what it means to build products that last. Not just visually, but structurally. Thoughtfully. Scientifically.

Because the right label doesn’t just stick—it sticks with people.

Study: Taste of Milk is Impacted by Its Packaging.

The dairy industry strives to preserve the quality and safety of milk products while maintaining the freshest possible taste for consumers. The industry has largely focused on packaging milk in light-blocking containers to preserve freshness, but more needs to be understood about how the packaging influences milk flavor. However, a new study in the Journal of Dairy Science®, published by Elsevier, confirms that packaging affects taste—and paperboard cartons do not preserve milk freshness as well as glass and plastic containers.

Lead investigator MaryAnne Drake, Ph.D., of the North Carolina State University Department of Food, Bioprocessing and Nutrition Sciences, Raleigh, NC, USA, explained that "milk is more susceptible to packaging-related off-flavors than many other beverages because of its mild, delicate taste." Besides light oxidation, "milk's taste can be impacted by the exchange of the packaging's compounds into the milk and by the packaging absorbing food flavors and aromas from the surrounding refrigeration environment."

To quantify the flavor impacts of packaging, the researchers examined pasteurized whole and skim milk stored in six half-pint containers:

Paperboard cartons

Three plastic jugs (made from different plastics)

A plastic bag

Glass as a control

The milk was stored in total darkness to control for light oxidation and kept cold at 4°C (39°F). The samples were tested on the first processing day, then again at 5, 10, and 15 days after. A trained panel examined the sensory properties of each sample, and the research team conducted a volatile compound analysis to understand how the packaging was intermingling with the milk. Finally, the samples underwent a blind consumer taste test on day 10 to see whether tasters could tell any difference between milk stored in the paperboard carton or the plastic jug compared with milk packaged in glass.

The results showed that package type does influence milk flavor, and skim milk is more susceptible to flavor impacts than whole milk. Of the different packaging types in this study, paperboard cartons and plastic bags preserved milk freshness the least due to the paperboard's absorption of milk flavor and the transfer of paperboard flavor into the milk. Milk packaged in paperboard cartons showed distinct off-flavors as well as the presence of compounds from the paperboard. The final results show that, while glass bottles remain an ideal container for preserving milk flavor, plastic containers provide additional benefits while also maintaining freshness in the absence of light exposure.

These findings are especially relevant for considering how young children consume and enjoy milk since paperboard cartons are the most widely used packaging for school meal programs in the United States. Therefore, industry and policymakers should seek new package alternatives for milk served at school since off-flavors may affect how young children perceive milk in both childhood and adulthood.

When it comes to enjoying the milk taste, the packaging plays an important role. Not only does it affect the taste of the milk, but it also helps to keep it fresh and safe. When milk is packaged correctly, it can help to preserve its unique flavor, texture, and appearance. If the packaging isn't done correctly, the milk can spoil quickly, leading to a change in flavor and an unpleasant taste. Milk packaging also plays an important role in preserving the nutritional qualities of the milk. Oxygen can get in and spoil the milk if the packaging is not airtight, causing the milk to become oxidized, which affects the taste and nutrition of the milk. 

Lead investigator MaryAnne Drake, Ph.D., of the North Carolina State University Department of Food, Bioprocessing and Nutrition Sciences, Raleigh, NC, USA, explained that "milk is more susceptible to packaging-related off-flavors than many other beverages because of its mild, delicate taste." Besides light oxidation, "milk's taste can be impacted by the exchange of the packaging's compounds into the milk and by the packaging absorbing food flavors and aromas from the surrounding refrigeration environment."

To quantify the flavor impacts of packaging, the researchers examined pasteurized whole and skim milk stored in six half-pint containers:

Paperboard cartons

Three plastic jugs (made from different plastics)

A plastic bag

Glass as a control

The milk was stored in total darkness to control for light oxidation and kept cold at 4°C (39°F). The samples were tested on the first processing day, then again at 5, 10, and 15 days after. A trained panel examined the sensory properties of each sample, and the research team conducted a volatile compound analysis to understand how the packaging was intermingling with the milk. Finally, the samples underwent a blind consumer taste test on day 10 to see whether tasters could tell any difference between milk stored in the paperboard carton or the plastic jug compared with milk packaged in glass.

The results showed that package type does influence milk flavor, and skim milk is more susceptible to flavor impacts than whole milk. Of the different packaging types in this study, paperboard cartons and plastic bag preserved milk freshness the least due to the paperboard's absorption of milk flavor and the transfer of paperboard flavor into the milk. Milk packaged in paperboard cartons showed distinct off-flavors as well as the presence of compounds from the paperboard. The final results show that, while glass bottles remain an ideal container for preserving milk flavor, plastic containers provide additional benefits while also maintaining freshness in the absence of light exposure.

These findings are especially relevant for considering how young children consume and enjoy milk since paperboard cartons are the most widely used packaging for school meal programs in the United States. Therefore, industry and policymakers should seek new package alternatives for milk served at school since off-flavors may affect how young children perceive milk in both childhood and adulthood.