Over the years I’ve received more than a handful of phone calls asking if there is a simple way to determine if a blank label is thermal transfer or direct thermal.
Direct Thermal Coating
The only difference between direct thermal material and thermal transfer material is the chemical coating present on direct thermal materials. I like to think of this coating as a while layer of “pixel bubbles” that get broken when heated or when the white barrier is removed. Generally, there is no way to tell just by looking at the label. Even when looking through a magnifying glass, the chemical coating is hard to see.
RighterTrack recently posted a short video (see below) with some tips on determining the type of thermal label material.
Scratch Test for Direct Thermal Label Coatings
Most direct thermal papers and films will show black where the material has been scratched. But, some direct thermal coatings are durable enough, so that the coating won’t scratch off as easily.
Heat Test for Direct Thermal Label Coatings
The foolproof method I use to determine the type of thermal label material is to apply some heat using a simple lighter. But I need to mention a disclaimer here: Perform this outside, making sure you are away from any gasses or combustible materials. DO NOT light the material on fire!! Simply do a quick swipe with the flame almost touching the material. If the material has a direct thermal coating, it will turn black and darken when heat is applied.
So next time you need to determine what type of thermal label material you have, give these tips a shot.