Direct-to-Film Printing: An Emerging Trend in Decorated Apparel
Direct-to-film printing (DTF) is a transfer technique that allows users to print designs onto PET film with water-based pigment inks. This article will provide an overview of this new technology, as well as compare it to other printing techniques.
- DTF is a better option than direct-to–garment (DTG), which requires fabric pretreatment.
- Preparing an image for print is very important. Hot-melt adhesive is applied using a hot melt powder made of polyurethane.
- DTF is a fast and cheap way to decorate fabrics.
By Johnny Shell
Introduction
Direct-to-film (DTF), a transfer technology that allows users to print designs onto PET film (polyethylene terephthalate) using water-based pigments, is one of the newest trends in the decorated apparel industry. The transfer technology means that the design will be printed in reverse order to traditional digital print. The image is reversed so that its orientation is mirrored—the CMYK colors (i.e., cyan, magenta, yellow, black) are printed first, followed by the white ink. The wet ink can be powdered using a hot-melt glue and then dried. After the ink has dried, you can transfer the image to apparel with a heat press.
What’s All the Buzz About?
DTF printing is more efficient than direct-to-garment printing (DTG). DTG printing requires fabric pre-treatment. DTF can also be used on fabrics such as nylon and polyester, which are difficult to print with DTG. In addition, there’s a much lower learning curve for printing DTF transfers compared to DTG. DTF allows the user to decorate more fabrics and colors than dye-sublimation. DTF is faster than other transfer techniques like heat-transfer Vinyl because it doesn’t require any cutting or weeding.
DTF can be used to create photorealistic full-color images, just like other digital print technologies. Only the range of inks used limits the color options. DTF can handle fine lines, small text, high-detail images, and even fine lines. However, it is possible to have difficulty with color profiling if you are not familiar with ICC profiles and color management. A special RIP software is required to create a white layer on the print and mirror the image to ensure the transfer prints are in the correct orientation.
The majority of DTF printers are from China. They are often modified Epson printers or platforms using Epson printheads (models commonly include 1–4 printheads). Additional printheads can be added to add white, CMYK or fluorescent channels. Print speeds will vary depending on the number and type of printheads. The available printer models are also divided into one of the following categories:
- Slow (25–35 sq. ft./hr.)
- Medium (80–100 sq. ft./hr.)
- Fast (150+ Sq. ft./hr.)
The cost per square foot for PET film, inks, and powder adhesive is between $0.50- $0.90. The washfast durability has been reported to be over 100 cycles.
Preparing the image for printing is important. However, hot-melt adhesive can be applied just like DTF. It uses hot-melt powder that is made from polyurethane resin and ground into adhesive powder. While there are no harmful emissions, the powder adhesive is exceptionally fine and can generate dust, so it’s important to wear respiratory protection when working with the powder. It’s also best to keep the inkjet printer at a safe distance from the powder coating process to keep adhesive dust from penetrating the sensitive parts inside the printer.
The powder comes in two colors, black or white depending on what color the fabric will be decorated with. Powder can be applied with an automatic powder shaker to apply PET film rolls, but it can also manually be applied by using PET film cut sheets. Applying the powder adhesive to a coating is crucial. Once cured, the transfer is applied at 315°F (157°C) for 15 seconds at medium pressure for cotton fabrics. You can reduce the time required to press heat-sensitive fabrics, such as polyester.
The newest offering in the industry is the CobraFlex DTF printers. These devices do not require powder adhesive. The transfer adhesive prints simultaneously with the white ink pass. This eliminates the need to use powder adhesive as well as the dust that it can produce. This is a new trend in inkjet printing, where chemistry is jetted along with CMYKW inks.
CobraFlex’s No Powder DTF Printer. Source: CobraFlex Printers
In just over two years, DTF has emerged as an “all-for-one” technology. DTF can be used to decorate many fabrics. It doesn’t require any pre-treatment and it is very durable.
The Bottom Line: Signs Of Movement
While today’s OEMs have been slow to react to market demand, there are signs of movement. Eastman Kodak Company launched its KODACOLOR Film to-Fabric ink system recently. The device comes with powder adhesive, PET film and an ink specifically for DTF transfers. Meanwhile, STS Inks (Boca Raton, Fla.) offers a device that uses Mutoh’s VJ-628, includes powder adhesive and PET film, and is branded with the STS logo.
Many OEMs, such as Epson and Kornit Digital, have promoted the possibility to print DTF transfer on their DTG devices with cut-sheet PET film or existing DTG Inks. It will be interesting to observe if other equipment manufacturers or ink producers decide to follow the DTF wave and develop dedicated printers. We will see what happens in the future, so keep checking back!
Johnny Shell is the Director of Keypoint Intelligence’s Functional & Industrial Printing Consulting Service. He is a respected leader and printing expert with more than 35 years of experience in the industry. Johnny is an inductee of Academy of Screen and Digital Printing Technologies. It is an international body of specialists that honors distinguished, long-term, and exemplary contributions to screen and digital print and associated imaging technologies.