Best Practices

Bar Coding for Beginners

Courtesy of Brodart Library Supplies & Furnishings

What is Bar Code Symbology and how does it work?

Symbology is a specific language represented by dark bars and lighter spaces that sends a number to your circulation software through a bar code scanner. A bar code is "read" when a beam or spot of light from a scanner is passed over the bar code. As the black bars absorb light and the spaces reflect light back to the scanner, the mathematical differences in reflection are translated into electrical signals. These signals are then converted into binary ones and zeros, which form various combinations equaling letters and numbers. There are three basic symbologies, or bar code formats, that most circulation software packages support: Codabar, Code 39 (Code 3 of 9), and Interleaved 2 of 5.

How do you determine which symbology to use?

Your circulation software determines which symbology you need. Each software package has its own "rules and regulations" governing the bar codes that will work with it. Each package may require a specific symbology; a special designator (numeric or alpha character) for patron or item label, a fixed or flexible total number of characters, as well as a required Check Digit. If you can't find your software's specifications in your software manual or you're unsure, call your software vendor and ask what symbology your software supports.

Choose bar code style: digital, laser or thermal. All three bar code label types are acid-free and are chemical- and UV-resistant. Digital and laser bar code labels are offered in laminated and non-laminated styles. Thermal bar code labels have a matte finish.

Digital bar codes are the latest in technology and most durable bar codes available. Imaged on 4-mil 60-lb. white paper with a 1-mil permanent archival-safe acrylic adhesive. Advantages include: 100% guaranteed first time read-rate; higher print-contrast ratio than photocomposed; archival quality; no change in adhesive; greater abrasion resistance than all other technologies; and a lower cost than photocomposed.
Laser bar codes are produced on a 1200 dpi printer on 24 lb. smudge-proof paper with a gloss or matte laminate coating for durability, and are available in five background colors plus white.
Thermal bar codes are printed on a 2-mil polyester material with a matte finish laminate for durability and are offered in four colors and three design configurations.

Choose bar code format: single, double or pairs.

Verify the quality by requesting a bar code sample. Good quality is essential for a good "read", and bar code label production varies. Some lower line production methods may produce voids in the inked area (bars) that may be misinterpreted as a space by the scanner, or the ink may "overspray" into the space area between the bars and cause a misread.
Use proper labeling procedures. Never use hand lotion before applying bar code labels. Depending on the print quality of the bar code and the substrate material of the label, hand lotion may cause ink to smear. Lotion may also cause the protector (if used) not to adhere properly to the label or even make grease spots on the label that can interfere with readability.
Using bar code label protectors. Quality protectors can extend the life of the bar code label by repelling dirt and other damage. Protectors also keep the coding information readable longer and eliminate lifting and peeling labels. Protectors specifically designed for use on bar code labels are best to use. Generic tape or protectors may lose quality, which increases the risk of damage to the bar code label and may hinder readability.

For more information, please contact:

Brodart Library Supplies & Furnishings. www.shopbrodart.com