What is the bar code
Barcode is a graphical presentation of information.
The information is encoded with dark and light stripes, determined by symbolism-specific code.
Barcode is designed for e-readers, additionally usually under the code there is placed the text representation of what was contained in the code.
It is designed to allow manual entry of code where the reader will not be able to read the information.
The use of codes
Barcode found the widest application in trade. The main use of the bar code is the automatic identification of products, which allows much faster, for example customer service at cash registers.
Nowadays it is practically impossible to find in store merchandise that hasn't got a bar code assigned.
If the shop gets merchandise that does not have an official barcode, the shop assigns custom barcode to it.
Even companies associated with the transport couldn't resist the popularity of barcode: every parcel, pallet is labeled with a barcode.
A key element that determines whether barcode fulfills its primary task is print quality.
The print quality is dependent on the nature of the ground and from techniques of reproduction.
Main reproduction problems: spreading of the paint, poor fixation of paint, too low contrast between the color of the substrate and the color bars.
Bar width reduction
One of the most common problems during reproduction is an increase in the thickness of the bar.
Each of the generators have the capability to reduce the width of the line.
This allows the generation of such a code, which after being printed will have the correct width of the bar.
That increases your chances of reading the code by the reader.
For barcodes EAN-8 and EAN-13 nominal bar width is 0.33 mm.
Using the bar width reduction must not lead to a situation where the thinnest bar will be less than 0.13 mm in the printing form.
If this happens, use a higher zoom ratio to (0.33 mm × magnification factor) - REDUCE WIDTH ≥ 0.13 mm.
no bar width reduction (BWR = 0)
with bar width reduction (BWR > 0)
For barcodes EAN-8 and EAN-13 it is recommended to use Coefficient of magnification in the range of 80% to 200% of the nominal size.
Each of the generators allows you to enter the zoom ratio in this range. Recommended zoom factors:
|Process and material
|Flexographic printing on paper and foil
|Flexographic printing on corrugated board
Wide to Narrow bar ratio („wide element” to „narrow element” ratio)
The wide-to-narrow ratio of a barcode is the relationship of narrow elements to wide elements.
Example: ratio 3, set width of „wide element” to 3-times larger than the „narrow element”.
Barcode created with ratio 2.5
„narrow element” - width 2px
„wide element” - width 5px
Barcode created with ratio 4.0
„narrow element” - width 2px
„wide element” - width 8px
The contrast between the base color and the color of bars
The most frequently used bar code readers are equipped with red light - 630 nm wave length.
Symbols are correctly read only if the prints with the printed code, lines dimensions, have got right overprint contrast.
Obtaining the contrast is dependent on both the background color and the color bars.
The background should as bright as possible and the lines should be at their darkest.
Background color should be: white, yellow, orange or bright red, and lines: black, blue, green and dark brown.
The accuracy of output devices
When reproducing the barcode accuracy of output devices must be considered.
Inkjet printer running at a resolution of 600 dpi is accurate to 0.0423 mm.
So if we print on the 0.33 mm bar we may receive a dash with a thickness from 0.29 mm to 0.37 mm.
An imagesetter, which is used to perform printing forms works usually with a resolution of 2540 dpi, gives the accuracy of 0.01 mm.
In this case, the bar width is between 0.32 mm and 0.34 mm.
Interleaved 2 of 5 barcode
Standard 2 of 5 barcode
Matrix 2 of 5 barcode
Codabar Rationalized barcode
MSI Plessey barcode
Pharmacode One Track barcode
Pharmacode Two Track barcode
Royalmail (RM4SCC) barcode