Thermal or Thermal Transfer?

Direct Thermal Labels
Print Head Life: Direct Thermal paper is in direct contact with the print head. Abrasion can reduce print head life by 30-50%, depending on maintenance and cleaning procedures.

Cost: The label cost is higher than a Thermal Transfer label, but no ribbon is required.

Downtime: There is only one consumable to change.

Print quality: Direct Thermal paper has a chemical coating, which reacts when heated to produce the print. This coating absorbs light, turning it grey or black, and the darkness of the print is lower than that produced by a thermal transfer ribbon. This can reduce the print contrast signal (PCS) of a barcode. PCS measures the difference between the bar and the background. Direct Thermal paper needs ideal operating conditions and high maintenance to repeatedly achieve perfect print quality.

Print speeds: The heat threshold to make the chemical reaction occur is much higher than for ink release on a ribbon, thus producing poorer print quality. Direct Thermal papers cannot run at speeds above 200mm/sec. Thermal Transfer can run at 350mm/sec. Increasing energy to the print head, to compensate, would dramatically reduce print head life.

Thermal Transfer Labels
Print Head Life: Print Head life is maximised because it is the self-lubricating ribbon, not the paper, which has contact with the print head.

Cost: A ribbon is required thus marginally increasing cost per print.

Downtime: There are two consumable items to replace.

Print quality: White labels with black ribbon produce exceptional quality print and achieve PCS in excess of 90%.

Print Speeds: Print speeds in excess of 350mm/sec are achievable.