GS1 Bar Code Verification For Linear Symbols

1 GS1 Bar code Verification For Linear Symbols GS1 Bar code Verification For Linear Symbols Version , May 2009 GS1 Bar code Verification For Linear Symbols Document Summary Document Item Current Value Document Title GS1 Bar code VerificationFor Linear Symbols Date Last Modified100 May 2009 Current Document Issue Version Status Final Document Description (one sentence summary)

2 Technical overview for applying ISO Verification to GS1 Linear Symbols . Contributors Name Organization See GS1 Bar code Verification Best Practice work team GS1 Log of Changes in Version Issue No. Date of Change Changed By Summary of Change Version May 2009 Wilson Silva Lutfi ilteris Oney Terms Update in line with the GS1 General Specifications January 2009 release. New Test Card pictures Disclaimer Whilst every effort has been made to ensure that the guidelines to use the GS1 standards contained in the document are correct, GS1 and any other party involved in the creation of the document HEREBY STATE that the document is provided without warranty, either expressed or implied, of accuracy or fitness for purpose, AND HEREBY DISCLAIM any liability, direct or indirect, for damages or loss relating to the use of the document.

3 The document may be modified, subject to developments in technology, changes to the standards, or new legal requirements. Several products and company names mentioned herein may be trademarks and/or registered trademarks of their respective companies. Publication History Original August 2000 Version January 2003 Version July 2003 Version March 2004 Version February 2006 Version March 2006 Version November 2006 Version February 2007 Version February 2009 Version May 2009 GS1 Bar code Verification For Linear Symbols Table of Contents 1.

4 Foreword .. 6 2. Introduction .. 7 3. What is Verification for? .. 8 Is Verification the only way of achieving good quality Symbols ? .. 8 What is a verifier? How does it differ from a scanner? .. 8 Why not just use a scanner to check readability? .. 9 Who needs to use Verification ? .. 9 Benefits .. 9 4. Verification techniques and history .. 10 Principal methodologies .. 10 Traditional Verification .. 10 ISO Verification .. 11 Equipment conformance standards .. 12 History of adoption in the GS1 General Specifications.

5 12 5. What Verification does and its limitations .. 14 6. When to verify .. 15 In symbol production .. 15 At the design stage .. 15 Film master/electronic origination/volume printing .. 15 On-demand printing .. 16 Post manufacture (finished goods despatch/receipt) .. 17 7. How to use a verifier .. 18 Importance of calibration .. 18 Calibration Frequency .. 18 Calibration materials .. 19 Calibrated Conformance Standard Test Card .. 19 Selection of aperture/light source .. 19 Scanning the symbol.

6 20 Hand-scanned verifiers .. 20 Automatically scanned verifiers .. 22 What additional steps need to be taken ( visual inspection)? .. 22 8. Scan reflectance profile analysis .. 23 What is a scan reflectance profile? .. 23 Pre-conditions for obtaining the profile (lighting, aperture) .. 23 Analysis of the profile and symbol grading .. 26 Parameters measured and their significance .. 29 29 Symbol Contrast (SC) .. 29 Minimum reflectance (Rmin) .. 30 GS1 Bar code Verification For Linear Symbols Edge contrast (EC).

7 31 Modulation (MOD) .. 31 Defects .. 31 Decodability .. 32 Bar width deviation (non-graded) .. 32 9. Interpreting the results .. 33 10. Potential causes of less-than-perfect grades .. 34 By parameters .. 34 Reflectance parameters .. 34 Other parameters .. 35 By printing types .. 39 Contrast in general .. 39 Measurements in general .. 40 Defects in general .. 40 Decode in general .. 40 Bar codes that fail to decode (general) .. 41 Thermal printing .. 41 Laser printer .. 42 Ink Jet printing.

8 42 Impact printing .. 42 High printing (book printing, flexography etc.) .. 43 Engraved printing (rotograuve) .. 43 Offset printing .. 43 By surface types .. 43 Corrugated board .. 43 Labels with metal .. 44 Film (foil) .. 44 Metals (cans) .. 44 Metal films with engraving .. 44 Non-opaque substrates .. 44 Glossy substrates .. 45 11. Using traditional measurements as part of quality .. 46 Print Contrast Signal and tolerances .. 46 Supplementing scan reflectance profile parameter grading with traditional measurements.

9 46 12. Considerations for GS1 System symbologies .. 47 Symbologies used in the GS1 System .. 47 EAN/UPC Symbology .. 47 GS1-128 Symbology .. 48 ITF-14 Symbols .. 49 GS1 DataBar .. 50 Other GS1 Symbologies .. 50 ANNEX A. Grade thresholds for scan reflectance parameters .. 52 ANNEX B. Use of Calibrated Conformance Standard Test Card .. 53 GS1 Bar code Verification For Linear Symbols ANNEX C. The process of symbol generation .. 55 ANNEX D. GS1 Bar code Verification Template.

10 59 ANNEX E. Selecting a Verifier .. 62 ANNEX F. Glossary of terms .. 65 GS1 Bar code Verification For Linear Symbols May 2009 Version Page 6 Copyright 2009 GS1 1. Foreword This GS1 Global Office publication has been developed with the intention of providing a clear explanation on the practical implications of Bar code Verification within the GS1 System. Although the target audience is GS1 Member Organisation staff involved in Bar code Verification , it is hoped that the information contained will be of use as a basis for training and/or reference material for specialists or end users involved in Bar code production and print quality.