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 can be used to decorate many fabrics. It does not require any fabric pre-treatment.
By Johnny Shell
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 hottest 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. After the ink has dried, it is powdered using a hot-melt adhesive. After the ink has dried, you can transfer the image to clothing with a heat press.
What’s All the Buzz About?
DTF can be used to print directly-to-garment (DTG), which allows for fabric pretreatment that is not required with DTG. DTF can be used to print fabrics such as nylon or polyester that are more difficult than DTG. In addition, there’s a much lower learning curve for printing DTF transfers compared to DTG. DTF can be used to decorate fabrics in a wider variety of colors and fabrics than dye-sublimation. DTF is more efficient than heat-transfer vinyl and other transfer technologies, as there is no cutting or weeding. This saves time.
DTF can be used to create photorealistic full-color images, just like other digital print technologies. The range of inks that are used will limit the possible color range. DTF is able to handle fine lines, small text and detailed images. Color profiling can be difficult for people who don’t know much about color management or ICC profiles. To create a white printing layer and mirror the image, special RIP software must be used. This will ensure that the transfer prints are in the right 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). You can add additional printheads to jet white, CMYK and fluorescent channels. Print speeds can vary depending on how many printheads are used. However, there are three types of printers available:
- Slow (25–35 sq. ft./hr.)
- Medium (80–100 sq. ft./hr.)
- Fast (150+ Sq. ft./hr.)
Prices per square foot (includes PET film, ink and powder adhesive), range from $0.50 to $0.90. The washfast durability has been reported to be over 100 cycles.
Preparing an image for print is very important. Hot-melt adhesive uses a hot melt powder made of polyurethane resin that has been 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 is available in black or white, depending on the color of the fabric to be decorated. Powder can be applied with an automatic powder shaker to apply PET film rolls, but it can also manually applied by using PET film cut sheets. It is important to apply the powder adhesive evenly. Once cured, the transfer is applied at 315°F (157°C) for 15 seconds at medium pressure for cotton fabrics. The press time for heat-sensitive fabrics such as polyester can be decreased.
The newest offering in the industry is the CobraFlex DTF printers. These devices do not require powder adhesive. This system eliminates the need for powder adhesive and the dust it can create. This is a new trend in inkjet printing, where chemistry is jetted along with CMYKW inks.
CobraFlex’s No Powder DTF Printer. Image 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. This ink system includes PET film, powder adhesive and ink specially designed for DTF transfer. 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 direct-to-garment OEMs such as Epson, Kornit Digital and OmniPrint International promote the possibility of printing DTF transfers using existing DTG inks and PET film. It will be interesting for other OEMs and ink makers to decide whether they want to join the DTF wave and develop dedicated printers, inks powder systems, PET films, or inks. 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.