Tips for testing the quality of data matrix codes
Increase the print quality with a few simple visual checks.
Additional and Special MAIL Services, dept. 31A2

General information

A data matrix code is comprised of black and white modules (boxes). A black module corresponds to the binary
value 1, and a white one to the value 0. Therefore the print quality is a decisive factor for a scanner to be able
to assess without a doubt which value a module has. Insufficient print quality may mean that the data matrix
code cannot be read.
Since hand scanners can have different read results, they are only suitable for checking the quality of the data
matrix codes to a certain extent.

In the following, you will find some information which will enable you to easily evaluate the print quality of a data
matrix code yourself as part of a visual check, using a standard linen tester where applicable. There is relevant
test equipment available in stores for further checks.
The ISO/IEC 15415 standard is used as a basis for checking the code quality of the data matrix code.

The quality of the printed data matrix code should as a matter of principle be “Grade A,” following the quality
parameters specified in this standard. In the case of deviations from this, Deutsche Post AG will need toperform a practice-related test to check whether the minimum quality necessary is being attained.

Deutsche Post

Tips for testing the quality of data matrix codes2

Physical size

Is the data matrix code the correct physical size?
Pressesendungen (Standard periodicals)(52 x 52 modules)

Letters, Dialogpost items, postcards:(26 x 26 modules)(22 x 22 modules)

11x 11 mm

9.3 x 9.3 mm

22 x 22 mm(16 x 48 modules)

Premiumadress Label

6.7 mm20.3 mm

7.6 x 7.6 mm

Tips and notes› If a data matrix code is printed smaller, then it cannormally no longer be read.
› Use a linen tester to check.
Deutsche Post

Tips for testing the quality of data matrix codes3

Contrast

Is the contrast adequate?

Good contrast

Modules are too light

Background is too dark

Tips and notes
Transparent labels or envelopes affect the read result.

Deutsche Post

Tips for testing the quality of data matrix codes4Modulation

Modulation: Are all modules equally dark?

Good modulation

Bad modulation(differences in brightness between the modules)

Tips and notes
Please contact the manufacturer of your printer if you
have any questions.
Use a linen tester to check.

Deutsche Post

Tips for testing the quality of data matrix codes5Fixed code patterns

Are the fixed code patterns (rhythmic pattern, quiet zone, search pattern) damaged?

Good and complete fixed code patterns

Search pattern damaged(e.g., printer head or drum unit is dirty

Tips and notes
Use a linen tester to check.

Deutsche PostTips for testing the quality of data matrix codes6Quiet zone

Has the quiet zone around the data matrix code been respected?
Quiet zone fully complied withQuiet zone not respected

Arndt Sender & Co., Sender Street. 1a, 12345 Sender town
Arndt Sender & Co., Sender Street. 1a, 12345 Sender town

Pierre Premium
Ph.D. in economics and social sciences
Premium Street 112345 Premium town

Pierre Premium
Ph.D. in economics and social sciences
Premium Street 112345 Premium town

Quiet zone (approx. 3 mm)

Deutsche Post

Tips for testing the quality of data matrix codes7

Axial non-uniformity

Axial non-uniformity: Are there deviations in the ratio between the width and height of the code and thus
between the individual modules (black and white boxes)?

Good form/linearity

Vertical non-linearity

Horizontal non-linearity

Tips and notes
Please contact the manufacturer of your printer if you
have any questions.
Deutsche Post

Tips for testing the quality of data matrix codes8

Grid non-linearity

Grid non-linearity: Are there deviations between the grid derived from the rhythmic pattern and the idealgrid?

Good grid/linearity

Distorted gridMoved grid(misalignment of the printer heads)

Deutsche Post

Tips for testing the quality of data matrix codes9Print growth

Print growth: Are all modules the same size?

Without print growth

Negative print growth

Positive print growthTips and notes

Print growth can be positive or negative. According to the printing techniqueand background, the printing can be too dark or too light.
Please contact the manufacturer of your printer if you have any questions.
Use a linen tester to check.

Deutsche Post

Tips for testing the quality of data matrix codes

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PREMIUMADRESS Service teamDeutsche Post AG
Adenauerallee 1830175 Hanover, Germany
www.deutschepost.de/premiumadress
www.premiumadress.de

www.deutschepost.deDeutschePost
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