As you may have noticed, we offer a Thermal Transfer finish as one of the options you can choose during a Quote or Order. What exactly does that mean?
Before diving into a detailed explanation of Thermal Transfer, we first need to understand that “Thermal Transfer” and “Direct Thermal” are two very different animals and should not be confused. Product labels are not suited to Direct Thermal treatment, so it's important to understand the difference. Direct Thermal printers rely on special heat-sensitive paper which create an image by applying heat directly to the required areas, which blackens the paper in those areas – common examples are gas station and restaurant receipts. It’s critical to understand that no ribbons are involved in this process – which is why it’s called “direct” thermal.
Conversely, “Thermal Transfer” printers use special ribbons with colored ink that gets melted by the printhead in the chosen areas and the ink “transferred” to the material being printed on (hence the name). This technology is often used by customers wishing to “overprint” product labels with variable data (such as expiry dates, lot numbers etc). In such cases, they leave a space in the label design specifically for this purpose – we print the main part of the label with all the fancy graphics etc and the customer then adds the variable content at a later time.
Here’s where it becomes tricky. In order for the Thermal Transfer inks to adhere properly to the pre-printed labels, we need to apply a special over-laminate during the initial printing that is specifically designed to accept the thermal transfer inks from the ribbons - normal laminates do not work well for this purpose and the inks will likely smudge or rub off completely.
So, if you do intend to over-print your beautiful labels with variable data, you will need to have a suitable printer in-house AND you also need the correct ribbons to match the special over-laminate we apply during the production process. Sorry to complicate it further still, but not all thermal transfer printers (or ribbons) are created equal. For example, there are wax ribbons, wax/resin ribbons and plain resin ribbons – all designed for different purposes. In the case of the thermal transfer over-laminate we carry, resin ribbons are usually the best bet (wax is least successful and wax-resin has mixed results).
With all that in mind, unless you’ve been down this road before and know exactly what to expect, it’s absolutely critical that you test some blank samples from us (which we’re happy to provide) on your own printer with your own ribbons. Never assume the combination of all the components will produce a workable result – there are too many things that can go horribly wrong unless you test thoroughly first.
Having done all that satisfactorily, you can then proceed to order your labels with confidence – choosing the “Thermal Transfer Laminate” option in the Label Finish section of your order so we know to apply that special over-laminate. Also remember that changing ribbon types or vendors later could easily undo all your good work – in which case further testing would be prudent.