Important Key Terms for Foam Packaging / Strategy / Last Modified: February 22, 2017

Foam packaging comes in a huge variety of sizes and shapes, from the little peanuts that fill up the empty spaces in boxes to 2000-foot ...

Foam packaging comes in a huge variety of sizes and shapes, from the little peanuts that fill up the empty spaces in boxes to 2000-foot rolls of foam wrapping sheets.  This guide covers some of the common terms you’ll hear from foam packaging vendors, including "anti-static", "engineered foam" and what the heck the difference is among polyethylene, polystyrene and polyurethane, as well as what "UPSable" means when applied to foam packing peanuts.

Loose fill, void fill or packing peanuts

They may look like peanuts, pasta shells, figure eights, or little S's (that lock to prevent settling) but they're all known as peanuts in the packing trade or loose fill or void fill. Pink-colored peanuts are anti-static, meaning they won't cling to your skin and clothes.
  See the pasta style peanuts at  

Anti-static or anti-stat

Many different types of foam packaging come in anti-static (sometimes called anti-stat) form, and depending on how resistant they are to electric charges, are called conductive, dissipative or insulative. Anti-stat foam packaging wraps sensitive electronics for shipment.
  See a variety of anti-static foam packaging at Uline.  To really geek out, here’s the standard for anti-static grading from the ASTM International.

Polyethylene, polystyrene, polyurethane

Three plastics that can be foamed for packaging. Polyurethane is the lightweight stuff used for pillows, but in packaging can protect delicate items. Polystyrene is the light but rigid material your takeout sandwich gets boxed in, and is best known by its Dow brand name, Styrofoam. Polyethylene is a tough foam that can protect heavy items against drops.
  Foam plastics maker Protexic goes into detail on the different polys.  Or see the plastics glossary at the American Chemistry Council.

Engineered foam

This is foam packaging custom designed to fit your product. The packaging may be created through molding or die-cutting or laminating pieces of foam together.
  UFP Technologies runs through its offerings for engineered foam packaging.


A foam packaging process in which liquid ingredients foam up inside a film wrapper or bag. This stuff can expand up to 200 times its liquid volume, saving you storage space.
  Sealed Air makes Instapak.


You'll see this term frequently in regards to peanuts: Vendors will break down an order into bags of seven cubic feet of peanuts that can ship by UPS oversize packaging to keep shipping costs down.
  See a UPSable deal at

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