Barcode Definitions: Auto ID Glossary

Barcoding technology and automatic identification (auto ID) systems are an integral part of supply chain logistics for enterprises. Because barcodes are machine readable and used by millions of companies across the world, there are global standards established for the structure of barcode data, along with standardized measurements for the quality, or readability, of the barcode.

Abbreviations and acronyms serve as short-hand for those in the industry, to help operations run smoothly and efficiently. However, for those unaware of the different barcode system definitions, the terminology can be confusing. Learn the important terms below.

What is a 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.

Barcoding Terminology - A-Z

1D Barcodes – A type of barcode that is one dimensional and encodes information with black and white parallel lines of varying widths and spacing. Also known as a linear barcode.

2D Barcodes – A type of barcode that is two dimensional and encodes information within a square or rectangle shape containing individual dots and white spaces of varying amounts, placement, and sizes. 2D barcodes were designed to increase data capacity beyond linear barcode symbols while still being readable by optical means. Two categories of two-dimensional symbols exist: multi-row (or stacked) and matrix.

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.

ADC – Automated Data Collection or Automated Data Capture – 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. ADC provides a quick, accurate, and cost-effective way to collect and enter data.

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.

Application Temperature – The temperature at the time the label is applied.

Backcoating – Used on a thermal transfer ribbon to prevent the ribbon from sticking to the printhead and to the substrate (media/label material). It also protects the printhead from excessive heat, static, and abrasion.

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

Bar – The darker element of a printed barcode symbol.

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.

Bearer bars – Some barcode symbologies are unsecure, meaning that if the barcode scan beam is partially off the barcode it may still result in a good read, although the data may be partial or incorrect. Bearer bars are bars at the top and bottom of the barcode bars that prevent partial reads. Code I 2 of 5 symbology contains bearer bars.

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 Font – Refers to the range and variety of data characters available within a given thermal printer model, for example 7 Bitmapped fonts type A,B,C,D,E,F and 1 Scalable font.

Character Set – (1)A range of data characters (alpha, numeric, and/or punctuation) that can be encoded into any given symbology. (2) Refers to the international characters and graphic symbols available within a given thermal printer model, for example IBM Code Page 850.

Check Character / Digit – A mechanically calculated number included within a string of data whose value is used for the purpose of performing a mathematical check to ensure that the barcode message is scanned and read correctly.

CISC Processor – Complex Instruction Set Computer Processor – the x86 and Pentium families use CISC processors that process complex instructions requiring less instructions per operation resulting in faster performance. However, the performance efficiency of a RISC processor can sometimes be affected by the software installed in the machine as newer, more complex software versions contain more instructions that the processor needs to process.

Codabar – A barcode symbology that uses four bars and three spaces to represent the numbers 0 through 9 and a set of special characters.

Code 11 – A barcode symbology developed by Intermec. It uses 11 characters: 0 through 9 and -.

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.

Code 49 – Introduced in 1987 by the Intermec Corporation as a multi-row, continuous, variable length symbology. Code 49 was the first stacked (two dimensional) barcode to receive widespread interest.

Code 93 – Code 93 is the complementary version of Code 39 and allows labels to be approximately 30 percent shorter than 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 Barcode – The end of each character in the barcode message marks the beginning of the next character; there are no intercharacter gaps to separate the characters in the barcode message, for example Interleaved 2 of 5 code.

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. Generally, the greater the contrast the easier it is for the reader to read the barcode, although some really reflective surfaces can cause problems.

Data Communications Equipment – (DCE) Devices designed to manipulate transmitted data, for example a modem.

Data Terminal Equipment – (DTE) A digital device such as a display terminal, data entry terminal, or printer which may be used to view or enter data. This device has a different communication connector pinout than DCE (see Data Communications Equipment).

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.

Direct Thermal Print – (DT) Direct thermal printing is an old technology originally designed for low cost copiers and fax machines. It has since been transformed into a highly successful technology for barcoding. The thermal printhead is typically a long linear array of tiny resistive heating elements (100-300/inch) arranged perpendicular to the paper flow. Each thermal printhead element locally heats an area on the chemically coated paper directly under the print element. This induces a chemical reaction which causes a dot to form in that area. The image is formed by building it from dot rows as the media passes underneath the active edge of the printhead. Direct thermal printing is an excellent choice for many barcode labeling applications. DT printers provide simplicity and environmental economy (recyclable materials are also available). Direct thermal printers are simple to operate compared to most other print technologies-with no ribbons or toners to replenish label loading is a very simple procedure. Enables batch or single label print capability with virtually no waste.

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

Dot Matrix Printing – A print technology that employs several needles that are evenly spaced across a moveable horizontal shuttle, which oscillates back and forth as the paper advances. Dot matrix printers print a barcode by creating overlapping adjacent dots to produce approximations of a straight edge line. Prints low to medium density barcodes that may not meet certain end-user guidelines. The dot size on the matrix printer limits the narrow element size and density of the barcode. Continuous ribbon re-use on dot matrix printers requires continuous monitoring of ribbon condition to ensure adequate barcode contrast. Ribbon ink that has become exhausted can produce an image that is inadequate for scanning. Ink saturated ribbon can result in paper “bleed” which can cause image distortion. Dot matrix printers are modified line printers that are most frequently used for printing batches of large labels with low density barcodes. Printing of single, individualized labels results in significant waste. The design of the matrix printer’s print carriage, sitting far below the media, also does not enable one to adequately maximize one’s label space.

DPI – Dots per inch (refer to Resolution)

DRAM – Dynamic Random Access Memory – is one type of chip used in Random Access Memory. It stores information as an electrical charge. Because this charge dissipates over time, the computing device must periodically run a “refresh cycle” on the chips to recharge them-hence “dynamic”. As it is a type of RAM, it will lose its information when the device into which it is installed is turned off. Typically, the time required to access information with a DRAM scheme is greater than with SRAM. SRAM chips cannot be substituted for DRAM chips; the machine (e.g. printer) must have been designed to use SRAM.

E3 – Element Energy Equalizer – Zebra’s sophisticated method of ensuring that the correct amount of heat is delivered to each part of a printhead at all print speeds in order to optimize the quality of the barcodes that are produced.

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.

EBCDIC – Extended Binary Coded Decimal Interchange Code was developed by IBM, and is used extensively in systems featuring IBM processors. Each character is represented by a six bit structure with the capability of generating 64 combinations.

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.

EDP – Electronic Data Processing – the act of processing information electronically.

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.

EPROM – The abbreviation for erasable programmable Read Only Memory – (See ROM).

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.

Error Correction Level – Redundant data correction and/or extra error correction in some barcode symbologies, allowing for some of the barcode to be missing and still result in a correct scan.

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.

Flash Memory – Read/Writeable RAM (a.k.a. Non-Volatile RAM) –  This is a type of Random Access Memory chip that does not lose its contents when its power is turned off; however, it can be intentionally written to, read from, and intentionally erased. It is a type of RAM and, hence, interacts with the computer or processor as described under “RAM” except that it does not lose its contents when power is removed. The advantage of flash is best understood by example:

A program or set of data could be stored into a computer or other machine at the place where the product is built. Of course, since flash won’t lose its contents even when it’s receiving no power, the product could be kept on the shelf with its memory loaded for a period of time before it’s put into service. While the product is in use, its flash chips cannot be accidentally reprogrammed, so the data or program that was stored in the product remains safely intact. At some point in the future, however, if the manufacturer of the product decided that there was a need to alter the data or the program, this could be done. The manufacturer would send to its customers a computer file containing the updated information. Along with the revised data or program would be a program for the product to use to erase the old data or program and read in the new information.

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.

Flood Coat – A thin coating of ink applied to the top of the printing screen by the flood bard or, in manual operations, by the squeegee prior to printing the stroke.

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

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

GTIN (Global Trade Item Number) – A globally identifier number for products. It is 14 digits and can be used to identify product information such as the retailer, manufacturer, and more.

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.

Heat Resistance – The property of a material which inhibits the occurrence of physical or chemical changes caused by exposure to high temperatures.

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.

Holding Power – The ability to withstand stress, as in holding rigid label materials on smaller diameter cylindrical objects or in holding weight.

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.

Impact Printing – Impact Printing, or dot matrix, is any printing system where a microprocessor-controlled hammer impacts against a ribbon and a substrate (label media).

Industry Standards – Created to encourage consistency across specific industries. Some of the more common standards are from the Automotive Industry Action Group (AIAG), Electronic Industry Association (EIA), the Healthcare Industry Barcode (HCIB), and the UCC Retail Pallet Format.

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.

Interlabel Gap – The space, notch, or hole between labels used by the media sensor on the printer to determine the label length and top of form.

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.

Inventory Control – Applications where bar coding and other forms of AIDC are used to add or delete items from inventory with 100% accuracy.

IPS – Inches per second (refer to Print Speed).

IrDa – Infrared Data Association – (1) A trade association. (2) A scanning technology that utilizes electromagnetic radiation wavelengths longer than those of visible light and shorter than those of microwaves.

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 oftentimes 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 scanner device using a low-energy laser light beam as its source of illumination.

Light Pen – A hand-held pen-like contact reader that 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 that 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.

LOGMARS – A Department of Defense (DoD) project on LOGistics applications of Marking and Reading Symbols resulted in the production of a new standard (MIL-STD-1189A) that led to the development of Code 39 as the established barcode symbology to be used by all DoD vendors.

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 barcode, 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 checkerboard. 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 that 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 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).

Memory – Zebra thermal printers contain a variety of memory options, including RAM, ROM, DRAM, SRAM, and Flash. For detailed descriptions of each memory option, refer to each herein by abbreviated name.

Mil – The narrowest nominal width unit of measure in a barcode. A unit of measure equal to 1/1000 of one inch. For example, a line 1/4 inch wide would be 250 mils.

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.

Moving Beam Barcode Reader – A scanning device where scanning motion is achieved by mechanically or electronically moving the optical geometry.

MSI – Barcode symbology made up of 4 bars and 4 spaces representing the characters 0 through 9.

Narrow to Wide Ratio – The ratio of the narrowest bar (see “X dimension”) to the widest bar in a linear barcode symbol. Common values are 2, 2.5, and 3. Just like X dimension, a larger ratio generally means better readability by the barcode scanner.

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 that do not require physical contact with the printed symbol.

Non-Continuous Media – Label, tag, or ticket that 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.

Null Modem Connector – A device that connects to the serial output of a print cable and switches pins 2 and 3, transmitted data signal, and received data signal.

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 that 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 that 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 that 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. Often used in the creation of Zebra media.

Polyethylene – A tough, sturdy plastic film having very good, low temperature characteristics. Often used in the creation of Zebra media.

Polypropylene – Similar to polyethylene but stronger, with a higher temperature resistance. Often used in the creation of Zebra media.

Postnet Code – A height modulated, numeric symbology developed by the U.S. Postal Service. This linear symbology that uses 5 bars and 4 spaces to encode each digit is unique in that the bars are of different heights to accommodate the fast printing process required by the post office as well as its resistance to smearing.

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 barcode, 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 (Quick Response) – 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 – The quiet zone is the minimum required space for barcode scannability preceding the Start Character and following the Stop Character of a barcode symbol. This is found to the left and to the right of the barcode symbol. This area should be free from any printing and be the same color and reflectance as the background of the barcode symbol. Also known as the Clear Area, this space provides the scanning device time to adjust to the measurements of each barcode in the message. The Quiet Zone should be ten times the width of the narrowest element in the barcode, or 0.25 inch minimum.

RAM – Random Access Memory – A machine’s main working memory. Program instructions and data are stored here. Each location in memory has a unique address, so the computer can access the information in any location at any time it’s required (i.e. “randomly”). RAM can be erased, written to, read from, and rewritten. It is erased when a computing device is turned off.

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 that 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.

RISC Processor – Reduced Instruction Set Computer Processor – reducing the number of instructions that a CPU supports will reduce the complexity of the chip, thus enhancing performance. However, the time it takes to fetch, decode, and execute the instruction may take longer than executing more code on a CISC processor. Examples of the RISC processors are the Hitachi SH1 and SH2. Also, the PowerPC uses RISC architecture.

ROM – Read Only Memory – Permanent memory, which can only be read, not written to nor erased. Typically programmed by the manufacturer carrying the software/instructions that a computer or similar device needs in order to get started every time it’s turned on. ROM does not lose its contents when the device it’s installed in is turned off.

Scalable Fonts – Refers to the inherent character and font sets found within a thermal printer and their respective ability to be adjusted and “shrunk to fit”. Scalable fonts are also commonly referred to as smooth fonts as their point sizes can be adjusted to any desired custom size evenly and proportionally, without the advent of visible rough edges.

Scan Spot – The size of the projection of light from a scanning device that “reads” the barcode message.

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

Self-Checking – A barcode is considered self-checking if a single printing defect will not cause a character to be transposed into another valid character in the same symbology.

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

Serial Interface – A link between data processing devices on which all the data moves over one wire, one bit at a time. Think of it as transmitting words one letter at a time until a total of 8 letters or bytes (8 bits) are received. The byte is then processed, but in a slower fashion than parallel. Common serial interface communications are RS232 C, RS422, and RS485 (9 or 25 Pin).

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.

Solvent – A dissolving, thinning, or reducing agent. Specifically, a solvent is a liquid that dissolves another substance.

Source Marking – The process of labeling an item with a barcode at the point of its initial production.

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.

Spectral Response – The variation in sensitivity of a reading device to the light of different wavelengths.

Specular Reflection – The mirror-like reflection of light from a surface.

Speed/Throughput – Used interchangeably to refer to a rate of motion or printer performance calculated in ips or inches per second. The higher the ips, the greater the printer’s performance rating.

Spot – The undesirable presence of ink or dirt in a space.

SRAM – Static Random Access Memory – is a type of memory chip used in Random Access Memory that can take advantage of a particular method of working with certain main processors. In brief, a certain spot in RAM is first accessed. Then each address after that first address is accessed in order, up to a specific point. Because the computer doesn’t have to “figure out” each sequential address to access, a large block of memory can be accessed in less time than is required with DRAM. Again, you can’t just substitute SRAM chips for DRAM chips; a machine must have been designed to use SRAM. As it is a type of RAM, it will lose its information when the device into which it is installed is turned off.

Stacked Code Symbols – See Two-Dimensional Barcode.

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.

Start Character – A special barcode character that tells the scanner to start and stop reading a barcode symbol. The start character is a unique character to the left of the barcode which allows for bidirectionality. In a vertical barcode, the start character is at the top.

Stop Character – A unique character to the right of the barcode which allows for bidirectionality. In a vertical barcode, the stop character is at the bottom.

Storage Temperature – Denotes the prescribed temperature range for the safe storage of a thermal printer.

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.

Symbology – A defined method of representing numeric or alphabetic characters in a barcode, or the language used in barcode technology (e.g. UPC, Code 39, etc).

Synthetic Substrate – Man-made materials which have been created for specific applications.

Tag Stock – Substrate which contains only the facestock and has a hole from which to be hung.

Tamperproof Label – A pressure-sensitive material that cannot be removed intact, thus making reuse of the label impossible.

Telepen – A continuous barcode which encodes the full ASCII character set.

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.

Throughput – Refers to the average length of label stock that a printer can process and print in a given amount of time. Throughput differs from print speed in that throughput includes the label transmission, formatting, and printing times. Due to these factors, a 12 ips machine may have lower throughput than a 10 ips printer.

Ticket – Substrate that contains only the facestock and contains no hole punches.

Tilt – Rotation of a barcode symbol about an axis perpendicular to the substrate.

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

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.

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.

Z Dimension – The achieved width of the narrow elements, calculated as the average of the narrow bar width and the average narrow space width.

ZPL/ZPL II – Zebra Programming Language – is the universal language/code of all Zebra barcode printers. ZPL is an ASCII based format that enables label generation to occur by way of an instructional blueprint defining label length, field origin, field data, and other related information. ZPL enables labels with any combination of text, barcode, or graphics to be created.

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