Bar Specifications

Standard Magnification

The following are the bar specifications and standards:

-	Barcode symbols are of overall regular shape made up of a series of light and dark parallel bars perpendicular to an imaginary base line or reference line, with a light margin on all sides.
-	The light and dark are composed of modules of uniform width, light or dark. ( In the following description of EAN symbols a dark module is represented by 1 and a light module is represented by 0.)
-	Characters in bar codes representing numerical digits are made up of seven (7) modules, light or dark.
-	In these characters the modules are grouped into bars, with each digit represented by two (2) light bars.
-	A dark or light space (bar) may consist of one (1) to four (4) modules
-	In addition to the numerical digit characters, there are auxiliary characters, consisting of few modules, used as guard bars (for beginning and ending) or center bar (for separation).
-	The symbol is designed to be read omni-directionally by a fixed-position scanner. It can also be read bi-directionally by hand held devices, such as a wand.
-	The symbol size is variable between limits in magnification, to accommodate the ranges in quality achievable by various printing processes and printing quality.
-	Dimensions are specified for one particular size , known as the nominal size (i.e. 1.0 magnification). Magnification limits are from 0.8 to 2.0 times the nominal size.

Symbol Scannability

To ensure the scannability of a bar code symbol, the complete bar code symbol has to be visible and clear, symbol specifications, must be respected. In particular the light margins (quite zone) which surround the symbol must be clear from any edge, overlap or crease or tight curve by at least 5 mm. This reduces the problem caused by scuffing, damage or distribution due to the package shape.

The size of the symbol must be calculated. The print contrast requirements must be followed. We would like to reiterate that the best color contrast is obtained with black bars and a white background.

Truncated Symbols

A bar code symbol is said to be truncated if the height of the bar has been reduced out of proposition to the width of the symbol.

As a general rule truncated symbols are not allowed.

The effect of truncation is to loose the omni-directional scanning capability of the bar symbol at the check out stores.

A reduced height (truncated) symbol can be scanned bi-directionally; for a successful scan the symbol on the package must be oriented in the direction of the of the scanning beam. A truncated symbol will reduce retail check out efficiency.

The more height is reduced, the more critical this orientation becomes. A symbol with more height reduction may therefore not be of any practically use at the checkout. Manufacturers with this particular problem are advised to consult with their customers to see if an acceptable compromise can be reached. Should truncation be the compromise solution then it is recommended that the reduction in height be no more than 20%.

Add-On Format

There are two (2) types of add-on symbols: the 2-digit add-on and the 5-digit add-on symbol. These symbols may be used in specific applications in combinations with EAN-13, UPC-A or UPC-E. The add-on has no right hand guard pattern. Nor does it have an explicit check digit. Checking is one through the mix of the number Sets A & B for the two or five digits as the case may be.

Human Readable Characters for Add-On

The numerical values of the bar characters shall be printed above in OCR-B font. It shall be placed in vertical correspondence with the bars. The upper edges of the OCR-B fonts shall be aligned with the upper edges of the main symbol.