How to Select the Right Label & Ribbon
Thermal transfer and direct thermal are two of options for printing variable data on tags and labels. WNS explains the differences between these technologies and how to select the right print method for your application.
What is Direct Thermal?
Direct thermal printing uses chemically treated, heat-sensitive label stock that darkens when exposed to heat from the thermal printhead. Leuco dye is the essential ingredient in the chemistry that allows this heat reaction to take place. Direct thermal printers have no ink, toner, or ribbon. This simple design makes direct thermal easy to use. However, because a printed direct thermal stock contains the chemistry to darken throughout its life, this darkening reaction can take place unintentionally whenever the material is exposed to high heat. Similar fading can occur with UV exposure. Direct thermal substrates include a select range of paper and film with varying levels of quality, depending on topcoats.
What is Thermal Transfer?
In thermal transfer printing, a thermal transfer ribbon is required to produce an image on thermal transfer receptive tags and labels. The media and ribbon travel together under the thermal printhead. As the printhead elements are heated, the ink is transferred from the ribbon to the receptive media to produce a printed label. The ribbon contains a backcoat that glides along the printhead and protects it from contact with the label surface extending the printhead life. There are a broad range of media and ink types that can be used for almost any application and durability requirement.
How to choose the right technology?
Direct thermal is well-suited for simpler applications that have a short life-span in environments with limited exposure to UV. While direct thermal requires only one media type, the label material is in direct and constant contact with the print head, which can increase wear and shorten the print head lifespan. By using varying label and ribbon formulations, thermal transfer printing can be used for a variety of applications, from simple everyday printing to harsh environment. Thermal transfer ribbons can more readily withstand heat, sunlight, abrasion and chemical exposure than direct thermal and as a result can produce higher print quality, durability and label longevity.
Selecting the right printer
Where do the labels or tags need to be printed? Direct thermal and thermal transfer printers are available in a variety of different options to fit your workflow. Printers range from portable printers for the mobile worker, stationary printers (printable from a desktop computer), and industrial printers for high-volume and quick speed for manufacturing and warehouse operations.