PrintShop Mail Expression Guide
Expressions BarCode Overview |
You can use the following barcode functions in PrintShop Mail:
A bar code can best be described as an “optical Morse code.” Series of black bars and white spaces of varying widths are printed on labels to uniquely identify items. The bar code labels are read with a scanner, which measures reflected light and interprets the code into numbers and letters that are passed on to a computer.
You must have a reader to read the bar codes into the computer. The reader includes:
An input device to scan the bar code
A decoder to convert the symbology to ASCII text
A cable to connect the device to your computer
Each symbology can encode a different number of characters in a given space with all other factors being the same. Numeric-only bar codes such as Interleaved 2 of 5 can encode many more numbers in a given space than a more flexible symbology, such as Code 128. In many cases this is critical. Even if one symbology is capable of making a bar code of the required size, you may get a better first read rate using a different symbology.
Checksums are additional characters appended to bar codes to guarantee good reads. Checksums are necessary on some bar codes that are prone to errors. For example, Interleaved 2 of 5 is a very dense, numeric-only bar code, but it is prone to substitution errors. You should always use a checksum on this code. Other codes, such as Code 128 and Code 39, are self-checking and seldom require a checksum.