Clamshell Packaging

A clamshell package is a thermoformed plastic package with two sides connected by a hinge or a seal. Many clamshells include a paperboard insert card promoting your product’s features and benefits. Most clamshells are sealed by RF sealing, but it can also be sealed by a tab in the package.

A variation of a clamshell is a tri-fold package, a one-piece clamshell with a flat base that allows the package to stand on the shelf.

Benefits of Clamshell PackagingClamshell Packaging

  • Improved sell-through – Products displayed in a clamshell package sell 4x better compared to the same product in other packaging styles. Through increased product visibility and a printed insert card, clamshell packaging allows you to use your packaging as a differentiation tool.

  • Increased protection – Using a clamshell package provides added protection for the product, retailer, and end-user. A custom thermoformed part holds the product in place, and reduces the chances of damage through shipping. On the shelf, the RF seal will reduce theft, helping to improve margins. Items that can be a hazard if used improperly, such as a knife, can be viewed safely via a sealed clamshell.

  • Adaptable to retailer’s demands – Retailer requirements are another factor to consider when choosing between packaging styles. Some retailer’s prefer to have products stand on-shelf, while other may make you hang your product on a peg. With a clamshell package, the customization options allow you to design your product without compromise.

Clamshell Insert Cards

An insert card provides value to consumers by showcasing your product’s features and instructions for use. The billboard space provided by clamshell packaging is one of its biggest benefits. The most common way to optimize this space is through a printed paperboard insert card.

Rohrer is a source for thermoformed clamshells and insert cards. This flexibility can save you the hassle of working with multiple suppliers for a single package. And because we are G7 Master Printer certified, you will get the best color management available.

Clamshell Sealing Options

The most popular method for sealing clamshell packages is through an RF sealing process, but there are various other methods available as well. Choosing the best option will depend on your product and protection needs. The most common methods for sealing clamshells are outlined below.

Radio Frequency (RF) Sealing

RF sealing uses electromagnetic energy similar to a microwave to heat and bond materials together under pressure. If you have a product that has to be securely sealed, this is the best option; it is the only method to guarantee a hermetic seal. RF sealing does not work well with all PET or RPET, and works best with PVC, PETG, and APET.

Hot/Cold Seal

Hot/Cold sealing connects plastic to plastic by using thermal energy and pressure to create a bond at the flange of a two-piece package. The bonding process is two stages, starting with a heat and pressure cycle that relaxes the plastic molecules, allowing the bond to be created. Next is a cool-down cycle that allows the seal area to stiffen. This method does not work with PET or RPET and does not create a seal as secure an RF seal. This process is typically used in smaller, lightweight packages and for electronics that may be damaged when using RF sealing.


Ultrasonic bonding is created by the mechanical action of high frequency “hammering” of overlapping plastic surfaces under pressure. A specially designed machine transfers vibratory motion into the plastic via a tool called a “horn”, causing the plastic to rapidly heat and melt. The horn holds the molten plastic pieces together under pressure until cooled. The tooling for this method is very expensive, and the size of the seal area is limited, which may require larger packages to be rotated multiple times to fully seal. However, the quick seal cycle makes this an attractive option for large-volume items.

UV Sealing

UV sealing involves the use of an adhesive that is activated by exposure to ultraviolet radiation. When exposed to certain levels of UV light, cross-linking of the polymer occurs and it begins to harden and create bonds with the plastic surface. Adhesive cure times range from one to thirty seconds. This process can provide unpredictable seals, but offers little to no tooling cost.

Impulse Sealing

A heat-sealing process that uses short bursts of energy to heat a sealing bar. The bar is then brought into contact with the mating parts of the package structure. The heat is only applied as long as needed, but the sealing bar remains in contact with the package until the seal is cooled and the bond is created. This process is simple and safe, but the relatively long seal times make this a better option for lower-volume items.

Additional Sealing Options

If your product does not require extensive pilferage resistance, there are other options available. For very small runs, using staples along the flange are a manual but inexpensive method to secure your product in the package. A seal can also be built into the package by designing button snaps to hold the two pieces of plastic together.

Stock vs. Custom Tooling

Deciding between stock and clamshell tooling? You can find an in-depth analysis and the best time to use both, here. When weighing your options for clamshell tooling consider volume, protection, as well as product differentiation. If you aren’t sure which tooling type you need, check out the list of features of each:

Tri-fold clamshellStock Clamshell Tooling

  • No tooling cost
  • Low minimum quantities
  • Faster lead times
  • Easy RFP process
  • Limited choice of sizes
  • Best when selling less than 10,000 units annually

Stock Tooling with Custom Product Cavity

  • Improved look over stock tooling
  • Increased product protection
  • Moderate tooling costs
  • Lead times of around three weeks
  • Offers budget-friendly product protection

Custom Clamshell Tooling

  • Packaging designed specifically for your product
  • Ability to incorporate additional features in packaging
  • Wider selection of materials
  • Higher perceived value over stock parts
  • Larger monetary and time investment
  • Promotes a premium brand look and identity

Click here to see all our stock tooling options

Best Industries for Clamshell Packaging

Clamshell packaging is a great option for protecting and displaying high-value products. Below are some of the industries where clamshells are commonly found:

  • Health & Beauty
  • Hardware
  • Electronic
  • Sporting Goods
  • Crafts & Hobbies
  • Toys
  • Food

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