Industry Glossary

High Density Polyethylene (HDPE)

HDPE bags are harder and have much stiffness with higher temperature resistance (non-porous). They are non-stretching and are not as clear as LDPE bags and considerably hazier. However, they are strong and tear-resistant.

Low Density Polyethylene (LDPE)

LDPE bags are softer, glossier and have more elasticity. They are porous, stretchable and have good clarity.  It is suitable for general packaging applications and trash collection.

Linear Low Density Polyethylene (LLDPE)

LLDPE bags have higher tensile strength, therefore tougher and better puncture/tear resistance as comparing to LDPE. They are non-porous and very stretchable.

Polypropylene (PP)

PP bags have the highest clarity and excellent material to protect moisture and vapors. It is non-porous, super clear, non-stretching and generally stronger and more rigid than PE. It is commonly used for packaging foods, crafts, photos, cards and scented products and preferred option for merchandise display.

Oriented Polypropylene (OPP)

OPP bags have good clarity, good printability and is moisture resistant. It serves as an excellent packaging material for artistic and retail products.

Four Process Colors: The four process colors (cyan, magenta, yellow and black) are also referred to as CMYK. However it is a myth that every image can be duplicated using the “four process colors.” Additional ‘spot’ colors are often required to generate the high resolution images that are most preferred in modern packaging.

Reverse Printing: The vast majority of all consumer is reverse printed. In this case, the outermost layer is printed on the back side and laminated to the rest of the multi-layer structure. While not mandatory in all industries, it is the preferred method for the food industry as it guarantees there will be no ink contact with the food product.

Shrink Films: Oriented films that are not heat-set after orientation. These films can shrink back close to their unstretched dimension at temperatures higher than the temperature of their orientation. See PVC Shrink Film, PET-G Shrink Film, and OPS Shrink Film.

Side-Gusset Bag: A bag with gussets on both sides, with a fin-seal running from top to bottom and sealed horizontally at the bottom and the top. Commonly used in the coffee industry.

Surface Print: The process where by the ink is deposited directly onto the outermost surface of the packaging film or material. The process is most commonly used in short run printing. A UV (ultraviolet) coating may be added to provide a hard exterior finish that prevents the ink from flaking or chipping.

Zipper Bag: A re-closeable or re-sealable pouch produced with a plastic track in which two plastic components interlock to provide a mechanism that allows for recloseablility in a flexible package. 

Flat Bag
Poly bag that has no side or bottom gussets. Can be made with or without a die cut handle.

Gauge
The thickness of poly material. Can be measured in mils (English) or microns (metric).

Gusset
The side and/or bottom measurements of a paper or poly bag.

Micron
The metric measurement used to describe the thickness of poly.
One micron is one one-thousandth of a mil.

SOS Bag
Self Opening Style. Four bag sides and bottom, with no handle, and serrated-top edge.
Generally known for use as lunch bags and grocery style in a variety of sizes.

T-Shirt Bag/SingletBag
A side gusseted poly bag with side strap handles. 

Soft Loop Handle Bag
A handled bag made with soft poly loops heat sealed to a folded top.
One of the most comfortable versions of poly bags.

Fold Over Die Cut Handle Bag
Poly bag in which the material at the top of the bag is folded over to the inside and heat sealed.
Fold over reinforcement provides double reinforcement around entire top.
Handle is an oval cut out within the fold over area.

Bottom Seal Bags
Individually cut bags from seamless tubing, sealed on the bottom. Flat or side gusseted bags with a strong seal – usually have a tail.

Biodegradable
Ability to completely break down, safely and relatively quickly, by natural or biological means, such as microorganisms like fungi, algae, bacteria, into raw materials of nature and then disappear into the environment. These products are not recyclable.

Degradability
Ability of materials to break down, by bacterial (biodegradable) or ultraviolet (photodegradable) action.

Recycled vs. Recyclable
Recycled: Products made from items recovered from waste.
Recyclable: Product that can be collected from waste for reuse.