Label Glossary

Label specifications can include unfamiliar terms related to materials, adhesives, printing, roll construction, RFID, barcodes, and chemical identification.

Use this glossary as a quick reference when reviewing OpStrata products, planning a label project, or requesting product assistance.

Label Construction and Roll Terms

Adhesive

The layer that bonds the label to a carton, container, product, bin, or other surface. Adhesives should be selected based on the surface, application temperature, environment, and required label life.

Application temperature

The temperature of the label and surface at the time the label is first applied. This may differ from the temperatures the label experiences after application.

Core size

The inside diameter of the cardboard or plastic center around which roll labels are wound. Core size must be compatible with the printer or label-handling equipment.

Facestock

The visible top layer of a label. The facestock is the material that receives printing and may be made from paper, polyester, polypropylene, or another material.

Label dimensions

The width and height of an individual label. Dimensions are generally listed as width by height.

Labels per roll

The number of individual labels contained on one roll.

Liner

The backing material that carries the labels before application. Labels are removed from the liner before being applied to the intended surface.

Outside diameter

The total diameter of a finished label roll, commonly abbreviated as OD. The roll OD must fit within the printer or external media holder.

Paper label

A label using a paper facestock. Paper labels are commonly used for controlled indoor shipping, inventory, warehouse, and identification applications.

Perforation

A separation line placed between labels or sections of the liner. Perforations make it easier to tear individual labels or groups of labels away from the roll.

Permanent adhesive

An adhesive designed to create a lasting bond to a suitable surface. Permanent does not mean the adhesive will work on every material or under every condition.

Removable adhesive

An adhesive designed to allow the label to be removed more cleanly from certain surfaces. Removability can change based on the surface, temperature, time, and environmental exposure.

Rolls per case

The number of individual rolls packaged together in one full case.

Service temperature

The temperature range the label is expected to experience after it has been applied and the adhesive has developed its bond.

Synthetic label

A label made with a non-paper facestock, such as polyester or polypropylene. Synthetic materials may provide greater resistance to moisture, tearing, abrasion, or environmental exposure, depending on the construction.

Winding direction

The direction and orientation in which labels are wound onto a roll. Winding direction can matter for certain printers, dispensers, and automated label applicators.

Printing Terms

Black-mark sensing

A media-sensing method in which the printer detects a printed black mark on the back of the liner to identify where each label or section begins.

Continuous media

Label or tag material without individual gaps or marks. The printer advances or cuts the material according to programmed lengths.

Direct thermal printing

A printing method that creates an image directly on heat-sensitive label material. Direct thermal labels do not require a ribbon.

Gap sensing

A media-sensing method in which the printer detects the space between individual labels.

Inkjet sheet labels

Sheet labels designed for use with compatible inkjet printers. Print quality and durability depend on the label material, ink, printer, and application.

Laser sheet labels

Sheet labels designed to withstand the heat and printing process of compatible laser printers.

Print method

The technology used to print the label, such as direct thermal, thermal transfer, laser, inkjet, flexographic, or digital printing.

Ribbon

A printing supply used by thermal transfer printers. Heat from the printhead transfers material from the ribbon onto the label surface.

OpStrata supplies thermal transfer labels but does not currently sell printing ribbons.

Thermal transfer printing

A printing method that uses heat and a compatible ribbon to transfer an image onto the label material. It is often selected when greater print durability or longer-term readability is needed.

Material and Performance Terms

Abrasion resistance

The ability of the label or printed image to withstand rubbing, scraping, handling, or contact with other surfaces.

Chemical resistance

The ability of a label construction or printed image to withstand exposure to a specific chemical under defined conditions.

Chemical resistance depends on the chemical, concentration, temperature, contact time, label material, adhesive, print method, and protective layers.

Moisture resistance

The ability of a label construction to withstand water, humidity, condensation, or other moisture exposure.

Polyester

A synthetic facestock often evaluated for applications requiring durability, dimensional stability, abrasion resistance, or longer-term identification.

Polypropylene

A synthetic facestock that may be considered when moisture resistance, flexibility, or conformability is important.

Surface energy

A characteristic of a material that affects how easily an adhesive bonds to it. Some plastics have lower surface energy and may require a specially selected adhesive.

Barcode and Identification Terms

Barcode

A machine-readable pattern that represents identifying information. A barcode normally requires a scanner or camera to have a clear optical view of the printed symbol.

GTIN

Global Trade Item Number. A standardized identifier used to identify trade items within the GS1 system.

A GTIN may be encoded in a barcode or used within certain RFID applications.

Human-readable information

Text or numbers printed on a label so a person can read the information without scanning equipment.

Serialization

The process of assigning a unique identifying number or code to each individual item, label, asset, or package.

Variable data

Information that changes from one label to the next, such as serial numbers, barcodes, lot numbers, dates, names, or unique identifiers.

RFID Terms

EPC

Electronic Product Code. A standardized identifier that can be encoded into certain RFID tags to identify an individual item or object.

Encoder

Equipment used to write information to an RFID chip. Some RFID printer-encoders can print visible information and encode the RFID inlay during the same process.

RFID

Radio-frequency identification. A technology that uses radio waves to identify and capture information from compatible tags or labels.

RFID chip

The integrated circuit within an RFID inlay. The chip stores and processes identifying information.

RFID inlay

The technology layer within an RFID label. It normally includes an antenna and an RFID chip mounted on a supporting material.

RFID reader

Equipment that communicates with compatible RFID tags or labels and sends captured information to a connected system.

RAIN RFID

A commonly used term for passive ultra-high-frequency RFID technology used in inventory, retail, logistics, supply-chain, and item-tracking applications.

Read range

The distance at which an RFID reader can successfully communicate with a tag.

Read range depends on the tag, reader, antenna, item, placement, orientation, packaging, and surrounding environment.

GHS and Chemical Labeling Terms

GHS

Globally Harmonized System of Classification and Labelling of Chemicals. GHS provides a standardized framework for communicating chemical hazards.

In the United States, GHS-based requirements are incorporated into OSHA’s Hazard Communication Standard.

Hazard statement

Standardized wording that describes the nature and, when appropriate, the degree of a chemical hazard.

Pictogram

A hazard symbol displayed within a defined border or shape to communicate a type of chemical hazard.

Under OSHA’s GHS-based system, required pictograms generally use a black symbol on a white background within a red diamond-shaped border.

Precautionary statement

Standardized wording that describes recommended measures for preventing or reducing harmful effects from exposure, handling, storage, or disposal.

Product identifier

The name or number used to identify a chemical product. The product identifier on the label should correspond with the identifier used on the safety data sheet.

Safety Data Sheet

A standardized document containing information about a chemical’s hazards, handling, storage, exposure controls, emergency measures, and other details. It is commonly abbreviated as SDS.

Signal word

A word used to indicate the relative severity of a chemical hazard.

Under OSHA’s GHS-based system, the signal words are generally Danger and Warning, with Danger used for more severe hazards.

Workplace label

A label used to identify and communicate hazards for a chemical container within a workplace. Workplace-labeling requirements and systems may differ from the complete labeling required for shipped chemical containers.

Ordering and Supply Terms

Case quantity

The number of rolls, sheets, or labels packaged together as a full case.

Custom label

A label produced to customer-specific requirements such as dimensions, material, adhesive, artwork, colors, finishing, or quantity.

Lead time

The expected time between approving or placing an order and the product being ready to ship or deliver.

Managed replenishment

A planned process for recurring label needs that may include expected quantities, ordering intervals, usage reviews, reminders, or scheduled shipments.

Reorder point

The inventory level that signals when the next order should begin. A reorder point generally accounts for average usage, lead time, shipping time, and safety stock.

Safety stock

Additional inventory maintained to help protect against unexpected demand, delays, or changes in usage.

Stock label

A standard label product offered in an established size, material, adhesive, and roll or sheet configuration.

Still Have Questions?

Label terminology can help narrow down your options, but the complete application still matters. Share your label size, print method, equipment requirements, surface, environment, and estimated quantity with our team.

 

The definitions on this page provide general educational information. Regulatory requirements, equipment compatibility, and label performance should be confirmed for the specific application.