For barcode label printing, there are two types of printing methods: direct thermal and thermal transfer. Each method uses a thermal printhead that applies heat to the surface being marked.



Direct Thermal Printing Method




Thermal Transfer Printing Method



Thermal transfer printing uses thermal transfer ribbon, and the ink from ribbon is absorbed during printing so that the image becomes part of the printed media. In this way, it creates durable, long-lasting printouts on a wide variety of materials, including paper, polyester, and polypropylene materials.

Direct thermal printing uses chemically treated, heat-sensitive media that blackens when it passes under the thermal printhead. It uses no ribbon, and produces the printout directly on thermal paper. Direct thermal media will fade over time gradually due to exposure of light, heat or other catalysts. The readability of direct thermal labels, wristbands, and receipt papers varies greatly, depending on the thermal paper quality and usage conditions.

                                                                                 



Direct thermal: 
Pros: cheaper, compact size, lower consumable cost.
Cons: Sensitive to light, heat and abrasion. only one type of printed material: thermal paper; printhead life will be reduced due to exposure to dust and debris.
Typical application: shipping labels, receipts, coupons, citations and parking tickets, compliance labels, patient wristbands, visitor passes, name tags, and more…

Thermal transfer: 
Pros: long-lasting printout suitable for lifetime identification applications, higher density, a variety of printed materials; longer life of printhead
Cons: higher price, bigger size which requires more room
Typical application: extremely durable inventory identification, asset tagging, sample and file tracking, certification labels, circuit board tracking, laboratory specimens, cold storage and freezers, and outdoor applications.

Printer Head Life: In direct thermal applications, dust and debris that may become present on labels are in direct contact with the print head. As these foreign materials are pulled across the print head, they may burn onto the elements or physically damage the elements resulting in poor print quality and/or premature print head failure. The same foreign material can exist in thermal transfer printing applications, but the debris would be between the label and the ribbon (i.e. not in contact with the print head elements) reducing the potential for damage.
Print head life in direct thermal printing applications is significantly reduced when compared to thermal transfer printing applications. 

In conclusion, direct thermal vs. thermal transfer listed as below:

  Direct Thermal Thermal Transfer
Provide durable, long-lasting printout   Y
Can be used in a wide variety of media and label surfaces   Y
Can create chemical resistant labels   Y
Longer life of printhead   Y
Lower printing cost (printer price lower, and ribbon is not reuqired for printing) Y