Why Have a Barcode?

Back in earlier times books were marked with a simple price tag on the cover. But if you look around a bookstore now, you’ll likely notice that nearly all the books have a barcode on the back cover; why is this necessary?

Although it is not law that you have a barcode on your retail product or publication, it is often required by re-sellers and distributors. They use the barcode to efficiently keep active inventories and sales records. Most retailers will no longer carry your book unless it has a barcode.

So how do barcodes work?
There are lots of types of barcode, but the common one we all see all the time is called UPC, the Universal Product Code.

Each digit is coded by two black and two white stripes. The stripes have widths of from 1 to 4 units, and the total width for each digit is always seven units.
This code is not quite all there is to it, however. Some digits of the barcode are reversed, so that they read right to left. Part of the code has black and white inverted, so black stripes are white and vice versa. This helps cut down errors and allows a computer to work out if the code was read from the wrong end when it was scanned.

The barcode is made up of 12 digits, in various groups. The first two show the country that issued the barcode. The next four digits indicate the manufacturer. Some countries have a three digit country code, so they only have three digits for the manufacturer code.

Example:
00-13 USA & Canada
20-29 reserved for local use (store/warehouse)
30 -37 France
400-440 Germany
45 Japan

There are some quirks in the system. Often books, which have the code 978, actually start the code with 78, so that there are enough digits left in the code to add the complete international book number. Sometimes the missing nine is simply printed in front of the code.

Most small manufacturers or self-publishers are pursuing barcodes to meet some requirement of a re-seller or distributor. This requirement should be specified by those re-sellers and distributors, and may differ from one to the next. There are industry standards, which are most often the requirements. Always check with your re-seller or distributor to make sure you meet their specifications.

Typically, after you obtain the ISBN for your book, you will have the ingredients to create your own barcode. Create a barcode yourself at Bar Codes Inc.
Learn more about barcodes at Bowker.

Article references:
http://www.morethanyouthink.com/shopping/barcodeswork.html
http://www.mecsw.com/info/UPC_FAQ.html