What One Needs To Know About Barcodes

As consumers we see barcodes used all the time, in stores for food products, stationary, outdoor appliances and even on our daily technology!

In June 1974, the first barcode appeared on a pack of Wrigley Company Chewing Gum. Barcodes are used for a variety of reasons including tracking products, prices, and stock levels for centralized recording in a computer software system.
There are two types of barcodes- linear and 2D. The most visually recognizable, the UPC (Universal Product Code), is a linear (1D) barcode made up of two parts: the barcode and the 12-digit UPC number. The first six numbers of the code is the manufacturer’s identification number. The next five digits represent the item’s number. The last number is called a check digit which enables the scanner to determine if the barcode was scanned correctly or not.
A linear barcode typically holds any type of text information.

In contrast, a 2D barcode is more complex and can include more information in the code; price, quantity, web address or image. A linear barcode scanner can’t read a 2D barcode; requiring the use of an image scanner for reading the information embedded in a 2D barcode.

Barcodes systematically represented data by varying in widths and spacing’s of parallel lines, and may be referred to as linear or one-dimensional (1D).


What is the difference between a UPC and an EAN code?
A UPC code is 12 digits in length and is known as “Universal Product Code”, an EAN code is 13 digits in length and stands for “European Article Number”. Originally barcodes were produces in UPC format, but as more countries started to buy into the barcoding system, it was decided to add an extra digit to enable countries to expand their quotas. Almost all scanners around the world are designed to be able to scan both formats.

Difference between an ISBN and ISSN barcode:
ISBN stands for International Standard Book Number, this meaning that it is used for all once-off publications such as books, novels, e-books.  ISSN stands for International Standard Serial Number and is needed to sell periodic publications such as magazines or newspapers. A unique ISSN or ISBN barcode is needed for each issue, variation or edition of publication.

How many barcodes does someone need?
For each and every variation of a product you will need a separate barcode number. I.e. if you are selling dark and light coloured paints in three different sizes, you will require 6 barcodes in total ( one for each colour in three sizes). This is required so that the store can keep track of the differing rates of sales on each individual product. You will also need a barcode for new products that are added to your line or brand over time.

What is a 1D (linear) and 2D barcode?
A 1D (linear) code is a very commonly used barcode that people are the most familiar with. There are several versions of linear barcodes and some encode only numbers while others can encode any keyboard character. These types of codes can be read by any types of barcode scanner. Linear barcodes arrange all information horizontally from left to right.
2D barcodes are a bit more complex as they organize information vertically and horizontally. This allows 2D barcodes to contain more information and take up less space than the linear barcode. 2D barcodes can’t be read by a normal linear scanner, they require an imager scanner to be read properly.

How many characters can fit into a barcode?
Linear barcodes can have from 20-25 characters while 2D codes go up to 2000 characters. As you increase the amount of information in the barcode the bigger it will become.

How small can a barcode be made?
Barcodes can come in a wide range of sizes, but trying to make it smaller would limit the amount of characters you use and will require a high resolution label printer to ensure the quality of the print is still readable by a scanner. The smaller the code becomes, the more difficult it is to read.

Who needs a UPC number?
If you sell products to a distributor or a retailer, you will need a UPC barcode. When you obtain your UPC number, you will also get a certificate authenticating your number. Most retailers require proof of the certificate to verify that your number is unique and authorized. Barcode South Africa is an advised and trusted website to purchase barcodes, they are recommended by Label Pro Industries and have great service and they are very professional.

What is a UPC barcode?
The UPC number itself is referred to as the GTIN (Global Trade Item Number). The GTIN is made up of two parts; the UPC Company Prefix and the number that you have assigned to that product: the first component, the UPC company prefix, is between 6 and 10 digits long and is assigned to you by Barcode SA. The number of digits is determined by how many products you will need to assign numbers to.  The second component is your unique number used to reference a specific product. It is generally referred to as the “Item Reference Number”. This number is the manufacturers choice on which unique code they would like for a given product.  The last number is a check digit calculated from the previous 11 digits. The barcode label printing software you use to create your labels will calculate this check digit for you.
How does a barcode scanner work?
A barcode scanner picks up the alternating black and white elements of the barcode which follow a specific algorithm that is turned into a corresponding text string by the scanner, this information is then sent over to your computer by the scanner no different than a standard keyboard.

Quality control and verification
Barcode verification examines scanability and the quality of the barcode in comparison to industry standards and specifications. Barcode verifiers are primarily used by businesses that print and use barcodes. It is very important to verify a barcode to ensure that any reader in the supply chain can successfully interpret a barcode with a lower error rate.

A barcode verifier works the way a reader does, but instead of simply decoding a barcode, a verifier performs a series of tests. for linear barcodes these tests are:
  • Edge determination
  • Minimum Reflectance
  • Symbol Contrast
  • Minimum Edge Contrast
  • Modulation
  • Defects
  • Decode
  • Decodability

2D matrix symbols look at parameters:
  • Symbol Contrast
  • Modulation
  • Decode
  • Unused Error Correction
  • Fixed (Finder) Pattern Damage
  • Grid Non-Uniformity
  • Axial Non-Uniformity

Barcode systems can provide detailed up-to-date information on the business, for example:
  • Fast selling items can be identified quickly and automatically reordered
  • Slow selling items can be identified, preventing inventory build up
  • Items may be repriced on the shelf to reflect both sale prices and price increase
  • Historical data can be used to predict seasonal fluctuations very accurately