A bar code is a series of lines and numbers that a machine can scan to find information about a product and the product's price. Generally, bar codes use parallel lines, but some use symbols, squares and dots. Bar codes are either eight or 12 digits. When referring to the size of a bar code, you are actually referring to the magnification of it. Bar codes must be within certain magnifications, or they will not scan correctly.
UPC Code Types
There are different Universal Product Codes: A, B, C, D and E. UPC A codes are most commonly used in grocery stores, splitting the numbers into two sections with a guard bar in the middle. UPC E codes are for packages, compressing the bar code by dropping the zeros that would normally show up in the code. The rest of the codes are not very common. UPC B is for the National Drug Code and National Health Related Items Code. UPC C is used to make products compatible industrywide. UPC D is a general product code with 12 digits.
UPC is used in the United States and Canada and can track products within stores or in transit. The nominal bar code is the middle point magnification of a bar code. It is a bar code set to 100 per cent magnification with a resulting size of 1.469 inches wide by 1.02 inches high. The standard bar code nominal X dimension is 13 thousandths of an inch.
UPC 80 Percent
UPC bar codes can range from 0.8 to 2.0 magnification. At 0.8, the bar code is reduced to 80 per cent from the nominal size. At this magnification, the bar code is 1.175 inches wide by 0.816 inches high. This is the smallest that a bar code can be and still be scanned. This size, however, does make it harder for machines to properly read the bar code information, and sometimes these will not scan at all.
UPC 200 Percent
This is the largest magnification recommended for a bar code. If you magnify it further, a machine may not properly read the bar code. The resulting dimensions are 2.938 inches wide by 2.04 inches high. You should try to use larger bar codes whenever possible. They scan better than the nominal and 80 per cent size bar codes.
European Article Number is the European version of the UPC bar code. EAN bar codes look and work the same way as UPC codes, except that they use a 13-digit number. The first 12 digits are the same as the UPC, and the 13th number is a check digit. Just like the UPC bar codes, you can magnify EANs to 80, 100 and 200 per cent of nominal. The resulting sizes are the same as the UPC symbols.