Thermal Transfer vs Direct Thermal

Put simply, the main two differences between these type of tags revolve around a ribbon being used/or not used and the labels overall lifespan. 

Thermal Transfer tags require a ribbon to print (which means the costs are generally higher) and this effectively makes them resistant to UV light and increases their lifespan. In contrast, Direct Thermal Tags don’t require a ribbon to print and they are susceptible to UV light and generally won't last as long.

Differences between Thermal Transfer and Direct Thermal

Features  Thermal Transfer Direct Thermal

Uses a ribbon

Yes No 
Durability High Low
Scratch resistant Yes No
Lifespan Longer lifespan Shorter lifespan
Suitable for Outdoor and harsh environments Indoor environments
How it works Uses ink to produce images Applies heat to produce images
General costs $0.13c per tag $0.10 per tag

Direct thermal and thermal transfer differences

PAT Tester Printers

With regards to PAT Tester brands – it’s important to understand who offers what before you make a large purchase. Some brands offer both Direct Thermal and Thermal Transfer, while others offer only one.

Lets break down exactly who uses what.

First off the rank is Seaward, and although they utilize a variety of different printers for their PAT testers (i.e. Primetest Pro Kit, PAC 3760DL Printer Pack and Elite Kit), all of them print solely with Direct Thermal. This is certainly a careful consideration you need to make as these will tend to suit warehouses or indoor environments. It's worth mentioning that many people that use Seaward testers still use Direct Thermal tags in outdoor environments.  

The ever popular Metrel brand is a mixed bag, with some units printing Thermal Transfer, while others Direct Thermal. PAT Testers kits that are specifically using the Zebra TPL and Godex printer will print Direct Thermal tags. The Zebra ZQ520 which is used with the Delta Pro Print Pack is the only Metrel kit that offers Thermal Transfer printing, but this of course comes with a higher price tag. 

Australian made testers by Wavecom specifically use Thermal Transfer tags for their Portable Appliance Testers, such as the TNP-500.

Pros and Cons of Thermal Transfer and Direct Thermal 

Thermal Transfer 

Pros Cons

Higher quality and better durability

More expensive option compared to others

Longer lifespan Needs a ribbon to run on a printer (additional cost)
Can be used outdoor or indoor  
UV resistant  
Text, images and barcodes are higher definition  

Direct Thermal

Pros Cons

Doesn't require a ribbon to print

Lesser quality means it might fade over time

More affordable than Thermal Transfer Can't be used in harsh environments

Which label is right for you?

Which label you end up choosing will depend mostly on your work requirements and its environment. To make your life easier, we have put together a printer label guide to help you choose the right label for your printer.  

If you’re someone who works in construction or any other kind of harsh environment, then Thermal Transfer will be the one you’ll need to use, no questions asked. 

However, a lot of businesses find Direct Thermal tags acceptable to use and will do the job, in which case that's fine to use as well (as long as their lifespan is long enough for your environment).

It's worth mentioning that there is a 'sort of' third option, which is the Thermal Transfer XL White Tags. These are unique in that they are extremely resistant to direct sunlight and heat - so if your label is being used outdoors, the label will give it the ultimate protection. The main drawback is that they scratch very easily when touched. 

Most PAT testers nowadays are moving towards Direct Thermal products, which on first glance does seem unusual considering their shorter lifespan, but this is certainly the trend we’re seeing from major test and tag brands.