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 printing is more efficient than direct-to-garment printing (DTG). DTG printing requires fabric pre-treatment.
- While preparation of the image to print is very important, it is just as important to apply the hot-melt glue. It uses a hot melt powder made of polyurethane epoxy resin that has been ground into adhesive powder.
- DTF is a fast and cheap way to decorate fabrics.
By Johnny Shell
Introduction
Direct-to film (DTF) is a new technology in decorated apparel that allows you to print your designs on polyethylene terephthalate(PET) film with water-based pigment inks. 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 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 can often prove difficult for 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 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. Only the range of inks used limits the color options. 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 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). You can add additional printheads to jet white, CMYK and 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.)
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 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. For printed PET film rolls, the best way to apply the powder is with an automatic powder shaker. However, it can also easily be applied manually using PET film sheets cut out. 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. You can reduce the time required to press heat-sensitive fabrics, such as polyester.
The newest offering in the industry is the CobraFlex DTF printer line. 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. Source: CobraFlex Printers
In just over two years, DTF has emerged as an “all-for-one” technology. It can decorate a wide variety of fabrics and does not require fabric pretreatment. Additionally, it is durable with great flexibility and stretchability and is cheaper than other options.
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, for example, recently launched the KODACOLOR film-to-fabric ink system. 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 to observe if other equipment manufacturers or ink producers decide to follow the DTF wave and develop dedicated printers. The future will be interesting, so please keep watching!
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.