What Are the Barcode Marking Methods and Types of Readers? 

Barcode readability depends on label material, printing method, and usage. 

Label printing

Different label types and printing methods are suitable for different purposes, impose different costs, and range in durability over time.

Common types of label printing include:  

• Inkjet printers, which are inexpensive, but the printing process is not. Inks tend to smear, so this method is only suitable for barcode printing if no other option is available.
• Laser printing, which is flexible and offers a range of fonts and layouts. It is inexpensive and common; however, it prints circles, which can weaken edge contrast.
• Thermal transfer printing, which is the most common method, where a heated print head melts ribbon ink onto the label. This method is highly durable and damage-resistant.  
• Direct-thermal printing, which uses a heated print head to mark thermally sensitive labels, changing the color to create the code. These codes have high resolution but fade over time, particularly when exposed to light or heat. 

Direct part marking

Label-based codes are not durable enough for parts exposed to harsh environments or components that must be identified throughout their manufacturing history. Similarly, medical devices are often placed inside a patient's body or have room for only a tiny code, making label-based codes impractical.

The solution is to engrave the code directly into an object, a process known as direct part marking. Since direct part marks (DPMs) are imprinted into an object, they inherently have a lower contrast than label-based codes and are generally harder to read.

However, DPMs have numerous benefits compared to label-based codes, such as:  

• Smaller code dimensions
• Improved durability
• Enabling tracking and tracing throughout an item’s entire lifecycle 

There are various ways to imprint a DPM. The best method depends on the material being marked and how the codes will be used. 

The most common methods of marking include: 

• Laser marking systems typically use fiber lasers to engrave Data Matrix codes or other 2D code symbologies on the part.
• Dot peen marking systems, generally considered the most cost-effective option, use an oscillating stylus to press into the metal, creating a divot.
• Chemical etching uses a sodium-based solution combined with a pulsing low-voltage electrical current. The charged solution dissolves the metal, which is then extracted through a special stencil. 

Types of barcode scanners 

Image-based barcode scanners

Image-based readers view the entire barcode, not just a single line, using advanced algorithms to overcome damaged or incomplete codes. In contrast, a laser scanner would generate a no-read for a damaged or incomplete code.  

Other benefits of image-based scanners include:  

• The ability to read 2D codes and DPMs
• Generally higher read-rate performance
• Decode damaged, incomplete, or obscured codes
• Barcode quality feedback
• The lower total cost of ownership, no moving parts
• Autofocus, lens, and lighting options to optimize read rates in different environments  

In addition, embedded and third-party applications can enable smartphones to read 2D label-based codes.  

Laser barcode scanners

Laser scanners use electronically controlled mirrors or prisms to project a laser beam horizontally. A sensor measures the reflected light and translates that into electrical pulses, which are converted into data by a decoder. That information is then forwarded to a processor through a cable or wireless signal.  

Because they are usually described by their use rather than their technology, a handheld barcode scanner might also be called a price scanner, a UPC scanner, an RF scanner, or a POS scanner. 

Handheld barcode scanners

Handheld barcode scanners are a staple in many retail applications. Logistics and manufacturing environments require more rugged handheld, oil, water, and damage-resistant readers. Industrial handheld scanners are often used to support fixed-mount scanning applications, when users need more maneuverability or to read codes in isolated locations or on cumbersome items.

Handheld scanners communicate information using a cable, Bluetooth, or Wi-Fi connection. Bluetooth and Wi-Fi are both wireless connection options, each with distinct benefits and use cases.