The History of Clamshell Packaging

Clamshell packaging is one of the most recognizable and widely used packaging formats in modern manufacturing and retail. Known for its hinged, shell-like design, the clamshell offers product visibility, durability, and protection while supporting efficient labeling and distribution. Its origins trace back to the late 20th century, alongside the rise of plastic thermoforming and mass-market retail goods.

Who invented clamshell packaging?

Clamshell packaging was patented in 1978 by U.S. inventor Thomas Jake Lunsford, who described the design as a “separable packaging and display system.” His invention introduced a hinged, single-piece plastic container that could securely enclose products while remaining transparent for retail display.

While Lunsford is generally credited with inventing clamshell packaging as a standardized retail packaging format, a closely related design appeared earlier in foodservice. In the early 1970s, Jon M. Huntsman Sr. developed a foam clamshell container for McDonald’s, most notably for the Big Mac. That design helped popularize the hinged container concept in quick-service restaurants, but Lunsford’s patent formalized its use across consumer goods and manufacturing.

What is clamshell packaging?

Clamshell packaging is a type of blister packaging made from pre-formed materials that enclose a product in a rigid or semi-rigid shell. The defining feature is a hinged closure, allowing the package to open and close like a clam.

A standard blister package consists of a formed pocket made from plastic or similar material, often sealed to a paperboard backing or another plastic surface. When that blister incorporates a hinge and closes onto itself, it is referred to as a clamshell.

The term “clamshell” comes from the package’s resemblance to a clam shell in both form and function: two rigid halves connected by a flexible hinge.

What is clamshell packaging made of?

Traditional clamshell packaging is commonly made from thermoformed plastics, including:

• Polystyrene (PS)
• Polyester (PET or RPET)
• PVC
• Foam sheets or expanded polystyrene

The package is typically formed using thermoforming or injection molding, with a single piece of material creating both the top and bottom halves. The hinge is formed from the same material rather than added as a separate component, which improves strength and reduces assembly complexity.

In response to sustainability concerns, newer clamshell designs may use paperboard, molded pulp, or hybrid materials that combine recycled paper with thin plastic films.

How clamshell packaging is made

Clamshell packaging is usually produced by heating plastic sheets until they become pliable, then forming them over a mold using vacuum or pressure. Once cooled, the material retains its shape, creating a rigid pocket with a flexible hinge.

This manufacturing approach allows for:

• Precise product fit
• Consistent wall thickness
• High production speeds
• Low material waste

The resulting packages can be shipped nested together, reducing storage space and transportation costs.

How clamshell packaging is sealed

Clamshells can be closed or sealed in several ways depending on the application:

• Integrated locking tabs or snap closures
• Friction-fit designs
• Adhesives or pressure-sensitive labels
• Staples or tape
• Heat sealing

In many retail and industrial use cases, labels also serve as tamper-evident seals, preventing the package from being opened without visible damage.

Why manufacturers use clamshell packaging

Clamshell packaging has remained popular for decades because it balances protection, visibility, and efficiency. Key benefits include:

• Clear product visibility for consumers
• Strong protection against damage, moisture, and contamination
• Reduced theft due to rigid enclosure
• Interchangeable inserts for similar product sizes
• Efficient nesting for shipping and storage

These advantages made clamshells especially popular for electronics, tools, hardware, food, and pharmaceutical products.

Environmental concerns and modern alternatives

Despite its benefits, clamshell packaging has contributed to a significant waste stream of rigid plastics. Recycling can be limited depending on material type and local infrastructure, particularly for PVC and mixed-material designs.

Around 2010, the packaging industry began introducing more sustainable blister and clamshell alternatives, including paperboard-based designs made from recycled materials. These solutions preserve the protective and display benefits of clamshells while improving recyclability and providing better surfaces for printed graphics.

Molded pulp and folding cartons can also be produced in clamshell-style formats, further reducing reliance on hard plastics.

Clamshell labeling and automation

Historically, labeling clamshell packaging was a labor-intensive manual process. Automated systems such as the EPI-9220 Clamshell Labeling System streamline this step by dispensing a label across the top, wrapping it around the front, and applying it to the bottom in a single motion.

This approach improves consistency, supports tamper evidence, and ensures accurate placement while reducing handling time. Automation has become increasingly important as manufacturers scale production and tighten quality requirements.

Frequently Asked Questions about Clamshell Packaging