Thermal Transfer Labels vs. Direct Thermal Labels
Which method is better and why?
Many of the questions we receive each week involve customers who have been tasked with finding the best label or printing solution and aren’t sure where to start. A common question that surfaces at the beginning of any label search is: “I noticed there are two main printing methods, thermal transfer printing and direct thermal printing. Which is the best method for me to use?”
The simple answer? Use direct thermal labels or printing systems when your application calls for temporary indoor labeling or general labeling. Use thermal transfer labels or printing systems when you need longer lasting labels that won’t smear or fade over time.
Here’s Why. Direct thermal and thermal transfer print technologies function different to get your data from the printer/software to your labels.
Direct thermal labels are created in a way that makes them sensitive to heat as they are chemically treated to blacken when the printhead applies heat to the label surface. An easy way to think of this process is to think of the printhead as a “stamp” that is burning your data onto the label surface. While this option is nice because you don’t have to usk ink, toner or ribbon for printing your data, your printhead is doing more work and you will need to replace it more often. Additionally, your labels are created to be sensitive to heat so if your application will be exposed to higher temperatures, your label could fade more easily.
Thermal transfer labels, on the other hand, require a ribbon to get the data onto your label. As the label stock passes through the printer, the printhead instantly melts the ribbon onto the label for a long lasting impression. Because the label itself isn’t designed to be heat sensitive, thermal transfer labels are typically built to last much longer and withstand more extreme temperatures and even chemicals. However, it is extremely important to note that you can’t just use any label stock with any ribbon, especially if your application requires your label to withstand any abnormal environments. There are a variety of different types of label materials that you can use and once you know your label material, you must choose a compatible wax, wax/resin or resin ribbon to print with. Choosing the right combination is critical as not all ribbon materials print on all label materials and you don’t want to be stuck with a roll of labels you can’t print on!
To sum it up:
Direct thermal labels are an affordable choice for short-term labeling (under 6 months) when used with applications like shipping/receiving labels, inventory labels, receipts, and tracking labels. They are not suitable for long-lasting identification because the direct thermal heat-sensitive material continues to darken when exposed to light and heat, and the text and barcodes fade over time. This makes your text unreadable and eventually makes your barcodes unscannable.
Thermal transfer labels are the reliable choice for high-performance identification. Your labels will not smear or fade and will remain legible and scannable for the long haul. Thermal transfer print technology offers more label stock choices than direct thermal such as paper, polypropylene, polyester, polyimide, Tedlar, vinyl, and more, as well as black and colored ribbons for color printing.
Although thermal transfer labels cost more than direct thermal labels, they allow you to print your UL/cUL recognized labels, product identification, asset tags, metallized rating plates, name plates, serial plates, outdoor identification, barcode labels, wire marking heat-shrink sleeves, high temperature circuit board labels (over 600-degrees F.), tamper-evident warranty labels, and more.
Whether you choose a direct thermal or thermal transfer printer will ultimately depend upon the nature of your application. Consider your maintenance costs, required label longevity, and label environment before you buy. If your application requires long-lasting, durable labels that resist extreme temperatures, chemical exposure, weatherability, and moisture, then thermal transfer is your best choice. If you have a short-term label application, then direct thermal would be an affordable option. Think you’ll need both? Some label printers offer direct thermal and thermal transfer in the same unit.
For assistance selecting a label printer or finding the right label stock and ribbon for your application, call Dasco toll-free at 1-877-855-2235, and we will help you find the best solution for your application.