Direct Thermal Vs Thermal Transfer

If you are looking for a barcode or label printer, you may have come across these printing technologies: direct thermal and thermal transfer. The two kinds of printing can easily confuse you if you don't understand the differences between them. These technologies produce high-quality printing barcodes, images, and text. Direct thermal printing uses a chemically treated heat-sensitive medium that darkens as it passes under the thermal print head. On the other side, thermal transfer printing uses a heated ribbon to create images on various materials.

The difference between direct thermal and thermal transfer

This article will show you the difference between direct thermal and thermal transfer, their pros, and cons and how to understand which printing technology will best suit your needs.

1. Direct Thermal Printing

Direct thermal prints without a ribbon, toner or ink but require a special kind of heat-sensitive material that darkens when you pass heat under it. Because the label is heat-sensitive if overexposed to heat, light, and other catalysts, it fades and becomes hard to read and scan over time.

Direct thermal printing is best for lengthy-lasting identification applications. Its readability depends on the usage conditions. Amazingly, this technology is excellent for various barcode printing applications that need to last less than 6 months, like receipt visitor identification, ticket printing and shipping labels.

How does a direct thermal printer work?

In direct thermal printing, the heating elements of the print head direct heat to the passing label, with heat-sensitive coating. The chemical reaction changes the color of the label from white to black.

Pros:

• Direct thermal printing produces a high-quality print with great scannability.
• It is ideal for applications that need to last less than 6 months, including receipts and shipping labels.
• Since the direct thermal printer does not require ink, toner, or ribbon to monitor, it is simple to operate compared to other printing technologies.
• You only need to replace the printable material in terms of maintenance, making maintenance costs remain low.
• The direct thermal allows both single and batches label printing.
• You can recycle material with this method of printing.
• A direct thermal printer is more durable than a matrix or laser printer, making it great for industrial and office applications.

Cons:

• The method tends to be extremely sensitive to environmental conditions, including light and heat.
• After printing, the papers remain chemically active, which is harmful to people and pets.

2. Thermal Transfer Printing

Thermal transfer technology uses wax ribbons which melt onto printing media and produces a durable and high-quality image. The thermal transfer printing is perfect for long-term applications that need to be used for more than 6 months and can be exposed to harsh conditions, including water, light, and chemicals, among others. For this reason, you can use this method for asset tracking, permanent identification, blood bags, outdoor applications, and cold and freezer storage.

Besides, the thermal transfer can be used on various printing materials such as polyester, paper, and plastic. These materials vary in durability, with polyester being the longest lasting. You can match label materials with different ribbons for maximum durability. Plus, the technology provides an option to use colored ribbons to enhance the label's appearance and streamline operations with a color-coded label.

Interestingly, some thermal transfer printers operate without ribbons. It is the right choice for small businesses that are not in a position to purchase multiple printers.

How does a thermal transfer printer work?

In thermal transfer printing, the passing ribbon is selectively heated by the print head's heating elements, melting onto the label and creating the printed image. The label absorbs the ink and becomes part of the substrate. The ribbon and label material should match to each other and the respective application for optimum quality and durability.

Pros:

• Thermal transfer produces high-quality graphics, text, and barcode print for maximum readability and scannability.
• Thermal transfer printing delivers long-lasting images.
• It allows both batch and single label printing.
• Thermal transfer maintenance cost is low compared to inkjet, dot matrix, and laser printing.
• This technology can print multiple media stocks.
• The printers tend to be more durable than a laser printer and dot matrix, making them suitable for industrial and office applications.

Cons:

• Because thermal transfer printers require ribbon, it is expensive.
• Its ribbon can't be recycled.
• For quality print, the ribbon and media substrate should be compatible.

Similarities between Direct Thermal and Thermal Transfer Labels

Both direct thermal and thermal transfer labels are categorized as thermal labels because they require heat when printing. The print heads apply heat to help create the image. Direct thermal and thermal transfer labels use the heat differently to display the print.

Another similarity is how both labels are supplied. They are sold in fanfold stacks or rolls. Fanfold labels are pre-stacked into bundled quantities for easy distribution, while rolls come in various core sizes and are easily installed into the printer system. You need to ensure the printer can accommodate the core size of the rolls.

The labels use a pressure-sensitive adhesive to stick with whatever surface they are applied to. The adhesive is user-friendly and is quick to apply. The adhesive eliminates the need for glue and other application methods such as water and heat-activated adhesive. The PSA ensures both thermal transfer and direct thermal labels perfect for medium to huge volume applications where quick stick capabilities must be like shipping environments.

Factors to Consider When Choosing Labels

Abrasion

A resin or wax ribbon will improve resistance to scratching and rubbing of your labels.

Surface

Various adhesives and materials are required for adhesion to form unique shapes like curved surfaces.

Chemical resistance

A thermal transfer label is needed if your label will be exposed to harsh environmental conditions such as water, heat, and chemicals. A high-durability resin ribbon is also resistant to these conditions.

Indoor/outdoor use

You can prefer thermal transfer labels for your outdoor conditions while direct thermal labels for indoor conditions.

Temperature

Direct thermal labels perform well at application temperatures of about 25°F to 200°F. However, a temperature above that will suit thermal transfer labeling.

Which one should you prefer?

Depending on your printing needs, you should choose one over the other.

You can consider direct thermal printing because it is great for shipping. The direct thermal label is printed, shipped after 3 days, and discarded with a package in 7-14 days. Since direct thermal printing offers more incredible reloading speed, there is no hassle of replacing a transfer label. In terms of durability, direct transfer labels tend to fade and smudge more quickly than thermal transfer labels. After 6 months, these labels can't be scanned.

Thermal transfer printing produces labels that are more resistant to smearing, smudging, and fading. It is suitable for archival purposes and long-term labeling needs. However, the method requires both labels and thermal ribbon, whose cost is close to direct thermal labels only. Although the thermal ribbon produces durable prints, it creates an extra hassle. Reloading the ribbon tends to be tricky since it is covered with printing wax, and you have to roll it properly.

How to decide

If you are still confused about whether to choose between a direct thermal printer and a thermal transfer printer, consider the following questions:

• Do you want to print labels in other colors apart from black?
• Does the label have a shelf life of over 1 year?
• Can the label be subjected to heat or light?
• Is the label prone to abuse or surface friction?
• Will you be printing high-density barcodes? If yes, do you have enough space?
• Will you print on various materials such as plastic, polyester, or paper?

If your answer is "yes" to all the questions above, you should consider a thermal transfer.

If "no," then direct thermal will be the perfect choice for you.

Frequently Asked Questions

What is the difference between Direct Thermal and Thermal Transfer Labels?

In a thermal transfer printer, it uses a ribbon to print. There are 3 types of ribbons, including wax, resin-based, and pure resin. Each ribbon is used for different applications depending on the label's durability and harsh environmental conditions. The printer uses heat to transfer the image from the ribbon to the label. The image is moved to the label with the positive side, and the ribbon will have the negative side. However, with thermal transfer, you are not limited to black color only; you can use colored ribbons. Lastly, it works well in any material and environment hence making the label long-lasting.

Direct thermal labels are heat sensitive and when it comes into contact with heat turns black. It does not require a ribbon to print. The direct thermal labels are great for printing shipping labels since they are not needed to last longer. Sunlight and heat will make the label turn black over time hence saving you time and money.

What is the least expensive type of label?

Direct thermal printers tend to be less expensive.

What type of label is right for me?

If you want your labels to be overexposed to sunlight or heat, or if you're going to print colored labels or want the labels to last for more than 6 months, consider thermal transfer labels. If you don't consider these factors, then direct thermal will suit you best.

Conclusion

Thermal printers are designed to print high-quality text, graphics, and labels. The main difference is that a thermal transfer printer uses a ribbon while direct thermal doesn't. Secondly, the thermal transfer involves the print head's heat elements to melt the ribbon and transfer the compounds to the labels to create images. On the other hand, a direct thermal printer uses print head heat on the label, causing the material to change color, creating an image.

Many companies find both printers efficient to run their business. It all depends on your specific needs.