Create EAN / GTIN codes: Tips for graphic artists

 

EAN codes are standard on every product today. While in the good old days, shopowners themselves typed the prices into a cash register by hand, today scanner cash registers are the rule, which scan standardized EAN codes with a laser and thus clearly recognize the article and add it to the receipt.

EAN, by the way, stands for “European Article Number” and was replaced in 2009 by the global GTIN, “Global Trade Item Number”. The EAN or GTIN is a barcode that can be read automatically and read by barcode readers.

For graphic designers in Europe, two standards from the almost infinite number of EAN codes in use worldwide are primarily important in the product area. EAN 13 and EAN 8, i.e. a barcode of either 13 or 8 digits. What do these numbers actually mean?

EAN 13:

  • The first three digits are the country prefix: 400 to 440 for Germany, 760 to 769 for Switzerland and Liechtenstein, 900 to 919 for Austria.
  • The following is a company number, which can be 4 to 6 characters long
  • Then follows an article number of the manufacturer, which can be 3 to 5 digits long
  • and finally a check digit, the 13th digit.

For books, for example, there is a separate EAN/GTIN 13 code in which the country prefix is replaced by a fictitious book country with the number 979 or 978 or for magazines 977. This is followed by a ten-digit ISBN or an eight-digit ISSN without check digit, which in the case of the short ISSN is usually completed by two zeros to 13 digits.

EAN 8:

  • The first 2 to 3 digits are the country prefix
  • Then follows an article number that is 4 to 5 digits long
  • and finally a check digit, the 8th digit

The EAN 8 code is a short code either for products where the EAN 13 code would take up too much space. But the most important application for EAN 8 is: All codes with the start number 2 can be used license-free within a company, but they are not unique worldwide compared to all other EAN numbers. Graphic designers most often come into contact with EAN 8 codes from companies such as ALDI and Co. that use this very possibility of internal codes.

  • Aldi Nord encodes its own products in the form 290X-XXXX, 290 is a “country number” for internal use.
  • Aldi Süd encodes its own products with an EAN-8 of the form 221X-XXXX

In addition, there are many other applications such as instore numbers, e.g. for selfweighed articles such as bananas, etc., in which the weight or price is included in the last digits.

With both codes, there is usually a text line under the line structure in which the 13 or 8 characters are usually printed in a machine-readable font such as OCR-B. In the event that the EAN code cannot be read mechanically, for example due to mechanical damage, the cashier can still read the 8 or 13 digits and enter them in the cash register.

What has to be considered when creating EAN codes?

The EAN 13 code consists of 113 elements of equal width, so-called modules, which are exactly 0.33mm (0.0130 inches) wide. On the sides must be a rest zone, also called brightfield from left 11 and right 7 module widths, before the start sequence, thus remain 95 modules for the actual code. It starts with a 101 sequence, i.e. a line sequence black-white-black left and right. In the middle of the code is a line sequence 01010, thus white-black-white-black-white incorporated. For the EAN 8 code the number of modules is limited to 81, the rest zone consists of 7 module widths each.

The standard EAN codes are 37.29 x 26.26 mm for EAN 13 and 26.73 x 21.64 mm for EAN 8 at 100% magnification. Important: The width does not only refer to the stitch code, but also includes the two rest zones, i.e. areas to be kept free minimally before and after the last bar. In the standard size, this is 3.63 mm on the left for EAN 13 and 2.31 mm on the right, and 2.31 mm on both sides for EAN 8.

The height of EAN codes can be reduced within certain limits, whereby a height of 50% of the EAN width should never be undercut. An EAN 13 code in standard format should therefore be at least 37.29: 2, i.e. 18.65 mm high.

In order to meet more flexible design requirements, the EAN codes can be reduced or enlarged, whereby the minimum format corresponds to 80% of the normal size and the maximum magnification 200% of the normal size.

In the past, defined enlargements and reductions for EAN 13 and EAN 8, as mentioned in SC0 to SC9, were permitted, which are still often communicated to graphic designers today. As a guideline, we have compiled the following table, whereby the magnifications and reductions are to be regarded only as a guideline. Between 81.8% and almost 84% can be found on the Internet for the size SC0 factor specifications, so the figures are not absolute, but rather for orientation.

SC0 to SC9: Magnification factors for EAN codes:

SC size / magnification factor / field dimensions B X H EAN 13 / field dimensions B X H EAN 8
SC0 / 82 % /  30,58 x 21,53 mm / 21,92 x 17,74 mm
SC1 / 91 % /  33,93 x 23,90 mm  / 24,32 x 19,69 mm
SC2 / 100 % /  37,29 x 26,26 mm / 26,73 x 21,64 mm
SC3 / 110 % /  41,02 x 28,88 mm / 29,40 x 23,80 mm
SC4 / 121 % / 45,12 x 31,78 mm / 32,34 x 26,19 mm
SC5 / 136 % /  50,71 x 35,17 mm / 36,35 x 29,43 mm
SC6 / 152 % / 56,68 x 39,91 mm / 40,63 x 32,89 mm
SC7 / 167 % / 62,27 x 43,85 mm / 44,64 x 36,14 mm
SC8 / 182% / 67,87 x 47,79 mm / 48,65 x 39,38 mm
SC9 / 197% / 73,46 x 51,73 mm / 52,66 x 42,63 mm

Enlargement factors have long been abolished, and barcodes between 80% and 200% are allowed at any magnification and reduction level. And the quiet zones have also been more flexibly regulated since 2010: A tolerance range of 0.8 module widths, i.e. around 11.5% of the rest zone for EAN-8, is permissible (left 1.0 module widths for EAN 13), whereby it is generally recommended to make the rest zone at least one module width wider than required. Even slight register misalignments or inaccuracies in the punching during final printing can otherwise easily make successful testing impossible.

In practice, however, there is another problem: Since EAN testing devices and the associated software are expensive, many companies only have testing hardware and software that is well over 10 years old. This means, for example, that the current tolerances of the rest zones are not stored in the software. In one case, for example, the preliminary test in the manufacturing company with outdated software from the beginning of 2000 marked the code as invalid due to insufficient rest zones, while ALDI, which is already equipped with modern software, would have easily passed with top marks due to the up to 8.5% higher tolerances since 2010.

Permissible colour combinations

The colours of the strokes and the background are also specified. Since the EAN is usually scanned with a red laser, it is important that the bars of the EAN code reflect red laser light between 633 and 670 nm only to a small extent, while the paper or background material, the sign carrier, must sufficiently reflect the laser light. The most important permissible colour combinations are therefore:

  • Background colours: white, yellow, red, magenta
  • Bar colours: black, blue, green, brown, cyan

Not all possible combinations are listed, but the important thing is: bars all carry at least cyan, backgrounds never. An inverse display is not permitted. Never use a background color as a bar color or a bar color as a background color.

Verification of EAN / GTIN codes

Optimum readability of barcodes is a decisive factor for recognition by barcode scanners. Poor print quality, gaps and spots, insufficient bright fields or a wrong magnification factor are often reasons for reading errors. And reading errors lead to obstructions of automated processes and mean costs due to manual intervention, e.g. by typing in the unreadable EAN code.

All well-known companies such as ALDI, Lidl, Hofer, Penny, Tschibo and many more insist on checking the code before manufacturing the product. The EAN codes are measured on special measuring instruments and evaluated with school marks. The criteria are:

  • edge contrast
  • symbol contrast
  • modulation
  • Rmin / Rmax
  • imperfection
  • decodability

Grades from A to F are awarded, corresponding to school grades 1 to 6. While ALDI, for example, requires at least a B, i.e. a school grade 2 in all disciplines, other companies are sometimes more accommodating. A scanner till would also be able to read EAN codes with school grade 5, but when checking the EAN codes it is important that the codes are as well and optimally readable as possible, even if they are dragged quickly or obliquely over the scanner at the till. But also a capped height, missing rest zones or transparent or reflective substrates are criteria for a devaluation or exclusion.

Proofing of EAN / GTIN codes

When proofing EAN or GTIN codes, the problem often occurs that checking the EAN codes often leads to worse results than with the end product printed in offset printing, for example. This is the fault of the proofing software manufacturers, who only paid attention to the color of the proof, but not to the line precision of the proofing software. Skin tones and bright colors were much more interesting for the software manufacturers than the correct representation of black lines on a white background. ALDI, for example, nowadays requires proofs for the release of a product that correspond not only in colour to the final product, but also in the decodability of the EAN / GTIN code.

The proofs of all common proofing systems fail here. Why? The fractions of a millimeter thin line on proofs usually have a considerable increase in width of up to 40%, while the white spaces are strongly restricted by the thick black lines. The result: normal proofs do not meet the strict criteria required by ALDI, Lidl and Hofer.

Together with a manufacturer of testing equipment, Proof.de has developed a solution for producing verifiable GTIN codes according to the strict ALDI guidelines on a legally binding, colour-accurate proof. This may require some effort, but the result is proofs that are not only color-accurate according to ISO 12647-7, but also meet the strict testing rules for EAN codes with at least a B grade. In the disciplines to be evaluated, the rules are five times the best grade A, i.e. 1, and once the grade B, i.e. school grade 2.

If you need such proofs or have any questions, please contact us.

Related Posts

 

3 thoughts on “Create EAN / GTIN codes: Tips for graphic artists

  1. Pingback: Kann man EAN/GTIN Barcodes prüfbar und farbrichtig proofen? | proof.de - Proof KnowHow rund um Proof, Farbproof, Digitalproof und Online Proof

  2. Hallo Herr Benz,
    Sie erwähnen, dass seit 2010 eine größere Toleranz bei der Messung der Ruhezonen existiert.
    in welcher ISO-Version wurde die Toleranz der Hellfleldzone neu geregelt? Wir finden in den uns vorliegenden Dokumentationen keinerlei Hinweise hierauf.
    Vielen Dank für eine Rückmeldung

    mfg

    Mathias Baier

    • Hallo Herr Baier,

      Franz Verweyen von REA Verifier in Mühltal wies mich darauf hin, der Hersteller des Verifiers und der Transwin Software, die die GTIN Codes auswerten kann.

      Konkret schrieb er mir vor ca. einem Jahr:
      “Die Bewertung der Einhaltung der mind. Ruhezonen von 7 x X-Modulgröße links und rechts von den Balken des Codes wird nach neuester Auslegung mit einer Toleranzzone von 0,8 x Modulgröße X vorgenommen.”

      Das sagt die GS1-Allgemeine Spezifikation in der aktuellen Version vom 3. August 2013, downloadbar unter http://www.gs1.ch/docs/default-source/gs1-system-document/genspecs/genspec-alle-kapitel.pdf?sfvrsn=10

      Unter 5.2.1.4.4. Ruhezonen (Hellzonen) steht:
      Die Mindestbreite einer Hellzone beträgt in der EAN/UPC Symbologie für das Hauptsymbol 7X. Für die verschiedenen Strichcodetypen sind, je nach Größe und Platzierung der Klarschriftzeile, unterschiedliche Breiten der Hellzonen definiert und im folgenden beschrieben (Abbildung 5.2.1.4.3 – 1):
      Für EAN 8: 7 Module oder 2,31 mm links und rechts bei einer Modulbreite von 0,330 mm.

      Laut diesem Absatz wären also die Modulbreiten jeweils links und rechts 7 Module breit. Aber:

      Auf Seite 316 finden Sie unter 5.5.3.3.10.2 den folgenden Hinweis:

      Zusätzliches Kriterium zur EAN/UPC Symbolklassifizierung
      Die Norm ISO/IEC 15416 berücksichtigt ein zusätzliches Kriterium zur Symbolklassifizierung gemäß Symbologiespezifikation. Für die EAN/UPC Symbologie sind die minimalen Hellzonen in Kapitel 5.2.1.4.4 definiert. Jedes einzelne Scanprofil, das diese Anforderung unter Berücksichtigung folgender Toleranzen nicht erfüllt, muss die Qualitätsklasse “0” erhalten.

      EAN-8: 6,2 Modulbreiten links, 6,2 Modulbreiten rechts !!!!

      Symbole unter der minimalen X-Dimension gemäß Abbildung 5.2.3.7 – 1 müssen die Qualitätsklasse “0” erhalten (siehe 5.5.3.4.3 für Ausnahmen). Anmerkung: Die Auswahl der minimalen Hellzonen basiert auf den ursprünglichen U.P.C. Qualitätsempfehlungen, als EAN-13 und EAN-8 noch nicht existierten. Minimale Hellzonen für diese Symbole wurden davon abgeleitet.

      Seit 2010 müsste laut Herrn Verwegen diese Regelung aktiv sein: 6,2 Modulbreiten links und rechts als Toleranz für die Messung. Im Zweifel laden Sie sich einfach das inzwischen 499-seitige Dokument der GS1 und lesen die Absätze selbst nach. Leider konnte ich aufgrund von schlechter Tabellenformatierung im Kommentarfeld die kompletten Tabellen der GSI hier nicht einkopieren.

      Ich hoffe, ich konnte Ihnen hier weiterhelfen. Viele Grüße

      Matthias Betz

Leave a Reply

Your email address will not be published. Required fields are marked *

AlphaOmega Captcha Classica  –  Enter Security Code