Bar Code Quality

Introduction

Bar code symbols are used to encode data. Encoding data means that the characters that we recognize as numbers or letters are converted by special printing software into the printed bars and spaces that make up a bar code symbol. How well a bar code can be scanned and the information extracted is influenced by many factors, such as packaging, type of scanner, operator interaction, and bar code print quality. This section addresses bar code quality or what needs to be considered to print bar codes properly so they have a high level of scanning success by others in the supply chain.

How is bar code quality determined?

Bar code quality is determined by precise measurements that are made by a device called a bar code verifier. A bar code verifier makes nine quality measurements that cover various aspects of bar code print quality. The overall quality is expressed in either a numerical or a letter grade ranging from zero (F) to 4.0 (A). The higher the grade the more likely that the symbol will scan successfully. GS1 standards set minimum quality measurements for each type of symbology and application. For example, printing UPC-A symbols for use in the retail environment requires a minimum passing grade of 1.5 or a C.

How can I learn more about bar code verification and bar code quality?

GS1 US provides several products that cover this topic, many of which are included in the Solutions Center.

Quality Control Practices for Bar Code Symbol Verification
U.P.C. Printed Symbol and Quality Specifications
GS1 General Specifications

Other related products include the Calibrated Conformance Standard Test Cards. These N.I.S.T. traceable standard cards are available for many of the linear symbologies implemented in the GS1 System. They are used to train operators of verifiers and are used to check the condition of the verifier to make sure that it is working within the tolerances specified by the manufacturers. Other products listed below are described in the Product Catalog.

Calibrated Conformance Standard Test Cards for GS1 DataBar (RSS), GS1-128, ITF, UPC-A, and EAN-13 Symbols
Symbol Contrast Gauge
Templates and Gauges
GS1 US offers special group training sessions