What is a bar code

Put simply, a bar code is nothing but a picture of numbers or characters. Below the bars you can see the characters and these are called a human readable field. Alpha characters should be avoided as you can see in the above example that they take up more space. This is because the most economical use of lines is allocated to numbers first. When you have a scanner connected, the scanner simply recognizes the bar sequences and send the numbers or characters to the computer in the same way as if you typed it on a keyboard. So, a bar code is very simple, scanning just types the number for you. Wherever your cursor is at the point you scan the characters will appear. Only software makes the bar code more useful.



What is a bar code

There are many kind of bar codes referred to as a symbology which is much like a different font for writing. The two basic groups are localized or international. In the example above the right hand image is an international symbology. This means you pay for an allocation of numbers that are unique to your company. The actual numbers refer to your country, company, item code. The very last digit is a check digit that ensures a legitimate scan. If you;re selling to a department store they may insist that you use one of these codes and you can get more information by clicking the "About GSI International Codes" link on the right. For the vast majority of Jewellers, a local code is all you need. They work as a basic barcode and will read fine on any system that has entered products with the barcode number as an indexed product code. Even your supplier or customers can use them as long as they have entered the numbers in their software. Remember it works like any other code you type by hand, if the product code is not there your software can't find it.



Printed example of Jewellery barcode

Assuming you just need a basic local barcode the industry standard is a symbology called Code 128. This symbology condensed well with good clarity between black lines and white space. It can also accommodate numbers of alpha characters making it very versatile. The tag size will be determined by the bar code size. You need to know the printer resolution, the scanner resolution, the maximum number of characters you will print and how wide that is, then add around 3mm white space before the bar code and 2mm after the barcode. Without the right amount of white space your codes will not scan correctly. ZETAGS offer a free sizing service. They also offer free remote support for the tags right through to the stage where you're finally printing and scanning. ZETAGS claim to be successfully scanning 3mm high bar codes due to the high clarity their tags offer. Regardless you should remember that you can't cheat on the width. The printer prints in dots which means codes scale in increments. Say the finest line is one dot wide. Make it wider and you need two dots, hence much wider. The height is not so important and can range from 3mm for high clarity materials up to whatever you need. Image above courtesy of ZETAGS