Glossary of Barcode Terms

Glossary of Common Barcode Terms

Auto ID Glossary of Terms


Accuracy – The determination of whether any element width or inter-character gap width (if applicable) differs from its nominal width by more than the printing tolerance.

AIDC – Automatic Identification and Data Collection – refers to all technologies that automate the process of data collection without the use of a keyboard, including barcode, magnetic stripe, (OCR) optical card reader, voice recognition, smart card, or (RFID) radio frequency identification. A

Adhesive – (1) A substance (cement, glue, gum) capable of holding materials together by surface contact. (2) The portion of a pressure sensitive label which allows the label to cling to its intended surface.

AIAG – Automotive Industry Action Group – a trade association responsible for creating automotive industry standards pertaining to barcode symbology and common label formats.

AIM – Automatic Identification Manufacturers, Inc. – a U.S. trade association headquartered in Pittsburgh, PA who represent the manufacturers of automatic identification systems.

Alignment – In an automatic identification system (Auto ID), the relative position and orientation of a scanner to the symbol.

Alphanumeric – A character set consisting of letters, numbers, and usually other characters such as special symbols.

ANSI – American National Standards Institute – a non-governmental organization responsible for the development of voluntary barcode quality standards. Barcode printing standards and the readability of barcode symbols are determined and classified into grades from A to F, to provide an overall symbol quality test.

Aperture – The opening on an optical system (scanner) that establishes the field of view.

Application – The particular use the label, tag, or ticket will serve once the barcode, text, or graphic image is applied.

Background – The spaces, quiet zones, and areas surrounding a printed symbol.

Bar – The darker element of a printed barcode symbol.

Barcode – A barcode is a piece of Automatic Identification Technology (Auto ID) that stores real time data. It is a series of vertical bars or a graphical bar pattern which can, (depending on the width and pattern) encode numbers and letters in a format which can easily be retrieved and interpreted by a barcode reader.

Barcode Character – A single group of bars and stripes that represents a specific quantity (often one) of numbers, letters, punctuation marks, or other symbols. This is the smallest subset of a barcode symbol that contains data.

Barcode Density – The number of characters that can be represented in a linear unit of measure. This number is often expressed in characters per inch or cpi.

Bar Height/Length – The bar dimension perpendicular to the bar width. Also called bar height. Scanning is performed in an axis perpendicular to the bar length.

Bar Width – The thickness of a bar measured from the edge closest to the symbol start character to the trailing edge of the same bar.

Bi-Directional – Barcode symbology capable of being read successfully independent of scanning direction.

Binary – A numbering system that uses only 1’s and 0’s.

Bit – An abbreviation for binary digit. A single element (0 or 1) in a binary number.

Bitmapped Font – Refers to the inherent character and font sets found within a thermal printer and their respective ability to be adjusted and “shrunk to fit”. Bitmapped fonts are commonly available in limited point sizes, for example 6, 8, 10, 12, 14, and 18 point, whose edges can become distorted or rough with manipulation outside the prescribed point size ranges.

Character – (1) A single group of bars and spaces that represents a specific number (usually one) of numbers, letters, punctuation marks, or other symbols. (2) A graphic shape representing a letter, numeral, or symbol. (3) A letter, digit, or other symbol that is used as part of the organization, control, or representation of data.

Character Alignment – The vertical or horizontal position of characters with respect to a given set of reference lines.

Character Density – Within a linear barcode symbol, the number of data characters per unit length (typically per inch). For a discrete symbology, the character width must include the intercharacter gap.

Character Set – (1)A range of data characters (alpha, numeric, and/or punctuation) that can be encoded into any given barcode symbology.

Code 128 – Code 128 is an alphanumeric barcode specifically designed to reduce the amount of space the barcode occupies. Each printed character can have one of three different meanings, depending on which of three different character sets are employed. Code 128 can be recognized as the labeling standard for UCC/EAN 128, used as product identification for container and pallet levels of retail markets.

Code 16K – This symbol is a stack of from 2 to 16 rows.

Code 39 – Code 39 is the most commonly used barcode. It can encode both numbers and letters, which is ideal for most industrial and non-retail applications. The Automotive industry uses Code 39 as its standard for shipping container labels. If you are just beginning a barcode application of your own, we recommend using Code 39.

Concatenation – The ability of a reading system to join together that data from multiple symbologies and interpret the information in a single message.

Continuous Media – Label, ticket, or tag stock media that does not contain any notches, gaps, or holes between each label. The label length must be specified in the label program.

Contrast – The difference in reflectance between the black and white (or bar and space) areas of a symbol.

Decoder – In a barcode reading system, the electronic package that receives signals from the scanner, performs the algorithm to interpret the signals into meaningful data, and provides the interface to other devices.

Depth of Field – The distance between the maximum and minimum plane in which a code reader is capable of reading symbols of a specified “X” dimension.

Diffuse Reflection – The component of reflected light that emanates in all directions from the reflecting surface.

Discrete Barcode – Each character of the barcode message stands alone, separated by intercharacter gaps, and can be read independently from the others.

DPI – Dots per inch (refer to Resolution)

EAN – The European Article Number is the European version of the UPC (Universal Product Code) barcode of retail food packaging that enables this linear barcode to be used internationally. Like the U.S. equivalent UPC code, there are two different types of EAN codes, EAN-8 and EAN-13.

EAN-13 – EAN-13 has 13 characters or symbols. It is very much like the UPC code and has the 13th character as a means of identifying in what country the product will be used.

EAN-8 – EAN-8 has a left-hand guard pattern, four odd parity digits, a center guard pattern, four even parity digits, and a right hand guard pattern with a total of eight symbols.

Edge Roughness – Irregularities in the printing of barcode elements, resulting in a non-uniform edge and edge errors.

EDI – Electronic Data Interchange – a method by which data is electronically transmitted from one point to another.

EIA – Electronic Industries Association – a trade association.

Electrostatic – A method of printing that utilizes a special electrostatic paper or charged drum, both of which attract toner to the charged area.

Element – A single bar or space in a barcode symbol.

ERP – Enterprise Resource Planning – a term used to describe a new wave of integration system software capabilities designed to link a company’s respective operations—including human resources, financials, manufacturing, and distribution—with their customers and suppliers.

Facestock – The part of the substrate (media) where printing occurs.

FACT – Federation of Automated Coding Technology – a bureau of AIM consisting of organizations that use and promote automatic identification among their members.

First Read Rate (FRR) – The ratio of the number of successful reads on the first scanning attempt to the number of attempts. Commonly expressed as a percentage and abbreviated as FRR.

Fixed Ratio – The ratio between the width of the bars in the code is a fixed standard and cannot be changed.

Flexographic Printing – The process whereby a pre-printed label, tag or ticket is printed by using a raised image plate surface to transfer wet ink to a printing substrate.

Gloss – Characteristic of the surface which causes it to reflect light at a given angle.

Guard Bars – Bars that are at both ends and center of a UPC and EAN symbol, that provide reference points for scanning. Guard bars are similar in function to start and stop characters.

Hand-Held Scanner – A hand-held scanning device used as a contact barcode reader or OCR (optical code) reader.

HIBCC – Health Industry Business Communications Council – a trade association responsible for the symbology and label format used by the healthcare industry.

High Density – This barcode type has narrow spaces and bars with an “X” dimension that is less than 7.5 mils.

Horizontal Barcode – A barcode or symbol presented in such a manner that its overall length dimension is parallel to the horizon. The bars are presented in an array that looks like a picket fence.

Human-Readable – The interpretation of barcode data, often printed immediately below the barcode in a readable format to humans.

IEEE – Institute of Electrical & Electronic Engineers – a trade association.

Industry Standards – Created to encourage consistency across specific industries. Retail, healthcare, automotive, defense for instance

Ink Jet Printing – Common direct marking process and a favorite on high speed production lines. Ink droplets are selectively deflected between a moving product and an ink return channel. Ink jet printing is frequently used for coding products and cartons with human readable data and lot codes at very high speed and for case coding of cartons with barcodes. Barcodes on corrugated boxes are intentionally made large so that dot placement accuracy becomes less critical, thus using more ink and creating questionable print quality and usefulness for bar coding.

Ink Layer – The bottom layer of a thermal ribbon which is composed of waxes, resins, or a combination of both.

Interleaved 2-of-5 – Interleaved 2-of-5 is a linear symbology that is most often used for encoding large amounts of information in a small area. Characters are paired together using bars to represent the first character and spaces to represent the second. Interleaved 2-of-5 barcode applications are prevalent in the electronics and manufacturing areas.

Label Thickness – Denotes the ideal range of media/substrate thickness designed to promote optimum print quality and printer performance.

Label, Pressure Sensitive – A pressure-sensitive label product is a die-cut part that has been converted through the production equipment using the type of pressure-sensitive material that has a protective backing. The end product is produced in the form of rolls, sheets, fanfold, or by other techniques that produce like products which have been slit or cut from the converted roll.

Label, Transparent – A pressure-sensitive label whose face material, adhesive, and protective coatings transmit light so that objects can be seen through it.

Ladder Orientation – A barcode symbol positioned vertically with horizontal bars and spaces.

Laminate – To apply one layer of material over another.

Laser Printing – The laser printer works much like a photocopier, projecting controlled streams of ions onto the surface of a print drum resulting in a charged image. The charged image then selectively attracts toner particles, transferring the image onto the paper substrate (media) by means of pressure. The pressure from the printhead and drum then fuse the image to the paper, creating the image. A laser printed label is only as durable as a photocopy of paper. Laser printers commonly cannot produce chemical- or water-resistant labels. Laser printer labeling adhesives must be carefully selected to ensure stability under the heat and pressure of the fuser.

Laser printers are not well suited for industrial labeling applications or individual product labeling applications. Compatible toners for thermal printing applications are often times lacking. Cost of toner is significant for barcode printing—15-30% black for barcode print versus 5% black for word processing print; 6 times the cost for bar coding using laser when compared to direct thermal or thermal transfer!

Laser Scanner – An optical barcode reading device using a low-energy laser light beam as its source of illumination.

Light Pen – A hand-held pen-like contact reader which the user must sweep across the barcode symbol in order to read the code. Also referred to as a wand.

Linear Barcode / Symbology – A complete barcode message is expressed in a single line of bars—also commonly referred to as a 1-Dimensional barcode.

Liner – The component of a label used to protect the adhesive and to keep it from sticking to objects before the label is used. It readily separates from the label immediately before the label is applied to the substrate. Also referred to as release liner, backing paper, or release paper.

Low Density – This barcode type has bars and spaces that are wide and far apart with an “X” dimension greater than 20 mils. This type of barcode is used for scanning barcodes from further distances.

Machine-Readable – A general term used for printed material that can be directly transferred to a data processing system.

Manufacturer’s ID – In the UPC code, the 6-digit number applied by the UCC to uniquely identify a manufacturer or company selling products under its own name. Also, the first 6 digits of the 12-digit UPC.

Matrix Symbols – Appear as a checker board. They are most likely square in shape, and contain some form of “finder pattern” which distinguishes them from other symbols. The finder pattern provides a decoding reference for scanners.

Maxicode – An example of a company which uses the Maxicode barcode is United Parcel Service (UPS). The next time you receive a package from UPS, look for a very small square with a pattern of dots and a small bulls eye in the center. UPS uses these barcodes as a way to sort their packages for a specific destination.

Media – (1) The term which refers to the label, tag, and/or ticket and its respective ribbon combination. (2) The surface on which a barcode symbol is printed. Also, interchangeably, referred to as substrate.

Media Roll Capacity – Refers to the maximum/minimum media roll diameter that a thermal printer can accommodate, for example 5.0” O.D. (Outer Diameter) and 1.0” I.D. (Inner Diameter).

Mil – The narrowest nominal width unit of measure in a barcode.

Misread – A condition that occurs when the data output of a reader does not agree with the data encoded in the barcode symbol.

Module – The narrowest nominal width unit of measure in a barcode symbol.

NIST – The National Institute of Electrical & Electronics Engineers – a trade association.

Nominal – The exact or ideal intended value for a specified parameter. Tolerances are specified as positive or negative values from this specified value.

Non-Contact Reader – Barcode readers which do not require physical contact with the printed symbol.

Non-Continuous Media – Label, tag, or ticket which contains either a gap, notch, or hole between each label.

Non-Read – The absence of data at the scanner output after an attempted scan due to no code, defective code, scanner failure, or operator error.

Numeric – A character set that includes only numbers.

OCR-A – An abbreviation commonly applied to the character set contained in ANSI Standard X3.17-1981. A stylized font choice used for traditional OCR printing.

ODETTE – The European equivalent of AIAG. See AIAG for further details.

Omnidirectional – Barcodes which can be read in any orientation in relation to the scanner.

On-Demand – A term used to describe when labels are printed immediately when the customer needs them and are ready for use, versus being sent off-site for printing.

One-Dimensional Barcode – A complete barcode message is expressed in a single line of bars. Also commonly referred to as a linear barcode.

Operating Temperature – Denotes the prescribed temperature range for the safe operation of a thermal printer.

Orientation – The alignment of a barcode symbol with respect to horizontal. Two possible orientations are horizontal and vertical bars and spaces (picket fence formation), and vertical with horizontal bars and stripes (ladder formation).

Overhead – The fixed number of characters required for start, stop, and checking in a given barcode symbol—a symbol requiring a start and stop character and two check characters contains four characters of overhead. To encode three characters with the overhead listed, seven characters are required to print.

Parallel Interface – A link between data processing devices on which the data moves over multiple wires and more quickly than serial interface. Imagine transmitting all 8 letters in a word at the same time over each wire. In parallel interface, the 8 bits (a byte) are received and then processed simultaneously. A common parallel interface option is Centronics (36 pin) parallel.

Parity Character – An optional character which may be included in the barcode message to minimize the misreading of the message.

PDF417 – A popular two-dimensional barcode that allows thousands of characters to be stored in its data format of multi-stacks. Some states use this type of barcode for driver’s license information. Healthcare facilities may also use the PDF417 for patient records because of the amount of data it can store.

Pen-Scanner – A pen-like device used to read barcodes. It can be connected either by wire to a device or be self-contained. Requires direct contact with the symbol.

Permanency – A measure of an adhesive’s ultimate holding power or bond strength. A permanent adhesive will develop a bond that makes label removal difficult or impossible without distorting the facestock.

Permanent Adhesive – An adhesive characterized by relatively high ultimate adhesion, but which can be removed. The degree of force used overcomes its bonding ability.

Picket Fence Orientation – A barcode symbol positioned horizontally with vertical bars and spaces.

Piggyback Label – A pressure-sensitive label which allows for dual usage. The construction consists of facestock, adhesive, and liner.

Pitch – Refers to the rotation of a barcode symbol about an axis parallel to the direction of the bars.

Plessey Code – A pulse-width modulated barcode commonly used for shelf marking in grocery stores.

Point of Sale (POS) – Refers to barcode related retail applications occurring at the point of sale.

Polyester – A strong film having good resistance to moisture, solvents, oils, and many other chemicals. Usually transparent, although available with metalized finish.

Polyethylene – A tough, sturdy plastic film having very good, low temperature characteristics.

Pre-Printed Symbol – A symbol that is printed in advance of application either on a label or on the article to be identified.

Pressure Sensitive Label – A pressure sensitive label product is a die-cut part that has been converted through the production equipment using the type of pressure sensitive material that has a protective backing. The end product is produced in the form of rolls, sheets, fanfold, or by other techniques that produce like products which have been slit or cut from the converted roll.

Print Length – Refers to the minimum and maximum label length a printer can print with standard or added memory capacity.

Print Method – Denotes the print technology used to print a label – commonly direct thermal or thermal transfer variety.

Print Quality – The measure of compliance of a barcode symbol to the requirements of dimensional tolerance, edge roughness, spots, voids, reflectance, PCS, quiet zone, and encodation.

Print Speed – The speed at which the label moves through the printhead, measured in inches per second (ips).

Print Width – Denotes the printhead width and the corresponding maximum label width on which a thermal printer can optimally print.

Product ID – In the UPC code, the 5-digit number assigned by a manufacturer to every consumer unit in its product catalog. The Product ID is different for every standard package (consumer unit) of the same product.

QR Code – A two-dimensional barcode developed for use in Japan that permits the encoding of binary, Kanji, JIS, and alphanumeric information.

Quality Control – Applications that use automatic identification to make sure the right material is in stock so it can be delivered for the right cost to the right user at the right time.

Quiet Zone – Barcode message overhead, which is an area to the left and to the right of the barcode symbol and is free of printing. This area provides the scanning device time to adjust to the measurements of each barcode in the message.

Reflectance – The ratio of the amount of light of a specified wavelength or series of wavelengths reflected from a test surface, to the amount of light reflected from a barium oxide or magnesium oxide standard.

Registration – Variation from label to label, of the position of what is printed onto the label as measured from the edges of the label.

Release Liner (Backing) – The portion of the pressure sensitive label which supports and holds the facestock and adhesive until application to the intended surface is needed.

Removable Adhesive – An adhesive characterized by relatively high cohesion strength and low ultimate adhesion. It can be removed easily from most substrate surfaces. Some adhesive transfer could take place, depending on the affinity of the adhesive to the surface.

Residue – Adhesive left on a substrate when a decal is removed.

Resolution – The narrowest element dimension that can be distinguished by a particular reading device or printed with a particular device or method. Generally the higher the resolution the better the resultant print quality. Measured in dots per inch (dpi).

Ribbon – A cloth or plastic tape coated with several layers of material, one of which is ink-like, that produces the visible marks on the substrate. Used on formed font impact, dot matrix, thermal transfer, and hot stamp printers. Also called foil.

Scanner – A device used to read a barcode symbol. It optically converts optical information into electrical signals.

SER – Substitution Error Rate, or the rate of occurrence of incorrect characters from an automatic identification system.

Service Temperature – The temperature range that a pressure sensitive label will withstand after a 72-hour residence time on the substrate. The range is expressed in degrees Fahrenheit and/or degrees Celsius.

Shelf Life – The period of time during which a product can be stored under specified conditions and still remain suitable for use.

Show-Through – The generally undesirable property of a substrate that permits underlying markings to be seen.

Skew – Rotation of a barcode symbol about an axis parallel to the symbol’s length.

Smudge Resistance – The resistance of a printed surface to smearing.

Space – The lighter element of a barcode usually formed by the background between the bars.

Space Width – The thickness of a space measured from the edge closest to the symbol’s start character to the trailing edge of the same space.

Standard – A set of rules, specifications, instructions, and directions on how to use a barcode or other automatic identification system to your advantage and profit. Usually issued by an organization, such as LOGMARS, HIBCC, UPC, etc.

Substitution Error – A misencodation, misread, or human key entry error where incorrect information is substituted for a character that was to be entered.

Substrate – The surface on which a barcode symbol is printed. Also, interchangeably, referred to as media.

Thermal Transfer Print – Thermal transfer printers use the same basic technology as direct thermal printers, but with the elimination of chemically-coated media in favor of a non-sensitized face stock and a special inked ribbon. A durable polyester ribbon film coated with a dry thermal transfer ink is placed between the thermal printhead and label. The thermal printhead is used to melt the ink onto the label surface, where it cools and anchors to the media surface. The polyester ribbon is then peeled away, leaving behind a stable, passive image. Consistent/sharp edge barcode print capability—with durable long-life and archival image stability. Clean, quiet, compact operation Batch or individual label print capability. Low cost/low maintenance compared to comparable technologies. Maximum readability and IR scannability. High contrast text, graphic, and barcode print capability. Durable for operation of joint office/industrial applications.

Two-Dimensional Barcode – Two-Dimensional Barcodes are special rectangular codes which ‘stack’ information in a manner allowing for more information storage in a smaller amount of space. These are also referred to as ‘Stacked’ Barcodes or ‘Matrix’ Barcodes. A standard barcode is limited to 20 to 25 characters.

UCC – Uniform Code Council – formerly the Uniform Product Code Council. The organization that administers the UPC and other retail standards.

UPC Code – Universal Product Code is the standard barcode symbol for retail food packages in the United States. This code was modified and adapted by Europe for international identification of food packages in the form of EAN.  UCC is now GS1.

UPC-A – UPC-A is the most common barcode used in retail today. It is a numeric, fixed ratio barcode with 12 characters.

UPC-E – A UPC symbol encoding six digits of data in an arrangement that occupies less area than a UPC-A symbol. Also called “zero suppressed” symbol because a 10-digit UPC-A code can be compressed to a six digit UPC-E format by suppressing redundant zeros.

Variable Length Code – A code whose number of encoded characters can be within a range, as opposed to a code with a fixed number of encoded characters.

Verifier – A device that makes measurements of the bars, spaces, quiet zones, and optical characteristics of a symbol to determine if the symbol meets the requirements of a specification or standard.

Vertical Barcode – A code pattern presented in such an orientation that the axis of the symbol from start to stop is perpendicular to the horizon. The individual bars are in an array that appears as rungs of a ladder.

Void – The undesirable absence of ink in a printed bar.

Wand/Wand Scanner – A handheld scanning device used as a contact barcode or OCR reader.

X Dimension – The “X”-dimension is the narrowest bar or space in the barcode. This bar or space is measured in millimeters (mil=1/1000 of an inch). The “X”-dimension defines the density of a linear symbology. Depending on what the “X”-dimension of a barcode is, the barcode will be called either high density or low density.