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Archive | Terminology

Similar to a dictionary for UL Terms, except it has articles. So actually more like an encyclopedia for UL Terms.

A Tale of Two Thermals

Direct Thermal Labels

Direct thermal and thermal transfer both use heat for imaging, but only one is approved for UL 969 labels. Do you know the difference? Admittedly because they sound similar, they can be easily confused. But each process requires very different materials–there is no one material fits all approach. In addition, permanency of the image varies wildly between the […]

NRTLs rhymes with Turtles

Slitting Anvil

Who or what are NRTLs and why should we care? Well the Nationally Recognized Testing Laboratory (NRTL)1 Program is a managed by the Occupational Safety & Health Administration (OSHA)2. OSHA was created in 1970 by Congress with the mission of overseeing working conditions and training in the United States. The majority of OSHA’s regulations fall into the category of general […]

UL Recognized Core Labels


“Make sure you have your core labels,” says pretty much every UL Inspector ever. One of the biggest reasons UL 969 labels are rejected by a UL Inspector is the lack of core labels. But what exactly are core labels, and why are they so important? Let’s start with the why. Let me walk you through this this […]