How are bar codes typically printed on labels?

Bar codes are typically printed on labels using a printer that creates patterns of lines. This method ensures that the bar code can be scanned effectively by barcode readers, which rely on the contrast between the black bars and the white spaces to interpret data. The specific patterns of lines represent numerical or alphanumeric information, which can be easily read by electronic devices.

Using a printer is crucial because it allows for precise and consistent creation of the bar codes, which is necessary for reliable scanning. Other methods, such as handwriting with a marker, would not provide the accuracy or durability needed for bar codes, and simply using numbers or special ink does not effectively convey the structure required for a bar code. Therefore, a printer designed to produce these patterns is the standard approach for generating bar code labels in various settings, from shipping to inventory management.