Digital Signal Processing, Gadgets, IT, Light, Telecomunications

Barcode types (Part 2)

After a long hiatus, I will give continuity to barcode types and its’ applications.

Barcode types (Part 1)Click here

Code 39 or Alpha 39


44 characters are used in code 39. Asterisks serve to indicate start and stop, but not always appear in these barcode types. Each character is made of 5 lines and 4 spaces, adding 9 elements, being 3 thick and 6 thin. That’s why has 39 in the name.

code 39

It’s size is variable, don’t use a check digit (except MOD 43 version). Code 39 ASCII complete includes small letters. This code is used in defense and automobile industries.

Code 93

code 93

It is a safer, more dense and compact version than code 39, used in military and automotive sector and, adopted by Canada Post to provide delivery information. Has more characters than code 39. Also has ASCII version, which includes small letters.

code 93

Interleaved 2 of 5

2 of 5 interleaved

Has variable length. Uses only number from 0 to 9 and number series must always have a pair number of digits. If series size is odd number, a zero must be added in beginning. Each digit is represented by 5 traits or spaces, 2 thick and 3 thin. That’s why the name is interleaved 2 of 5. It’s applied in tokens, airline tickets, inventories, envelopes, clocks tickets and 135 films.

Códigos de barras

In logistics it is used in ITF-14 code to identify cardboard boxes and product packaging.

Code 128

Code 128

The name is due to capacity to codify all 128 ASCII characters. Possess high density and it’s applied in supply and transport of goods. The code 128 is divided in following parts.

code 128

Code 128 can be classified in set A, B or C.

  • 128A set: Uses capita letters, numbers from 0 to 9, special and control characters.
  • 128B set: Uses small and capital letters, numbers from 0 to 9 and special characters.
  • 128C set: Adopts only numbers in pairs, from 00 to 99.

GS1-128 or EAN-128


Derived from code 128. Allows to code additional information like expiration date, price, quantity, recipient, dimensions, volume, area, etc. Applied in supply chain.



Adopts numbers from 0 to 9, symbols (-, $, :, /, + and dot) and capital letters A, B, C and D, as start and stop characters. It is used by FedEx, blood banks and in book spines in libraries.

Actually, this type is being replaced by others which can store more information in smaller space.



While the rest of barcodes types codify characters with bars and space lengths, postnet codifies base on height of bars. Uses digits from 0 to 9 and each one is codified with 5 strokes.


Like all barcode types, has a quiet zone. Frames bars mark start and stop of code and last digit is for check.

This type is used in correspondence.







About Pedro Ney Stroski

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