Direct-to-Film Printing: An Emerging Trend in Decorated Apparel

• DTF is a better option than DTG for printing direct to garment (DTG). DTF allows you to skip fabric pre-treatment which is sometimes required with DTG.
• Preparing the print image is important. However, hot-melt adhesive can be applied to the same images as DTF. It uses hot-melt resin made from polyurethane resin that has been ground into adhesive powder.
• DTF is a fast and cheap way to add color and texture to a broad range of fabrics.

By Johnny Shell

Introduction

Direct-to-film printing (DTF), a transfer technology that allows users to print design onto PET film with water-based pigment inks, is one of the most popular trends in the decorated apparel sector. The transfer technology means that the order of the printed design will be reversed to what is used for traditional digital printing. 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. Once dry, the wet ink can be powdered using a hot melt adhesive. After the ink has dried, you can transfer it to clothes using a heat press.

What’s All the Buzz About?

DTF can be used to print directly-to-garment (DTG), which allows for fabric pre-treatment that is not required with DTG. DTF also works on nylon and polyester fabrics, which can be difficult for DTG. In addition, there’s a much lower learning curve for printing DTF transfers compared to DTG. DTF can be used to embellish a larger variety of fabrics than dye-sublimation. DTF works faster than heat-transfer vinyl and other transfer techniques like dye-sublimation. DTF does not require any cutting or weeding, so it is more time efficient.

DTF, like other digital printing technologies, is excellent for creating photorealistic, full-color images. There are only a few limitations to the color range that can be achieved by using different inks. DTF can handle small lines, fine text and detailed images. However, it is possible to have difficulty with color profiling if you are not familiar with ICC profiles and color management. To create a white printing layer, and mirror the image to ensure the proper orientation of the transfer prints, special RIP software must be used.

China has produced the largest number of DTF printers to date. 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 can vary depending on how many printheads are used. However, there are three types of printers available:

1. Slow (25–35 sq. ft./hr.)
2. Medium (80–100 sq. ft./hr.)
3. Rapid (150+ Sq. ft./hr.)

Prices per square foot include PET film, ink and powder adhesive and range from $0.50 to $0.90. According to the report, washfast durability exceeds 100 cycles.

The preparation of the image to print is very important. Hot-melt adhesive uses a powdered polyurethane resin which is 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. Powder can be applied with an automated powder shaker to apply PET film rolls, or manually 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.

CobraFlex’s latest line of DTF printers is the best in their class. These devices don’t require powder adhesive. This allows the transfer adhesive to print simultaneously with white ink, eliminating both the powdered adhesive process and any dust that it may generate. Inkjet printing is embracing this new trend, where chemistry can be 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 pretreatment and it is very durable.

Let’s get to the bottom of it: Movement Signs

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. The device comes with powder adhesive and PET film as well as ink specifically 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.

This was in addition to the fact that many OEMs of direct-to garments, such as Epson, Kornit Digital and OmniPrint International, have promoted DTF transfers using their DTG devices. They can also print DTF transfers with existing DTGinks or PET film. Watch out for other ink and equipment manufacturers to jump on board the DTF train by creating dedicated printers, inks systems, powder systems, PET films, or OEMs. 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. A recognized leader and printing expert, Shell has over 35 years’ experience in the industry. Johnny was elected an inductee to the Academy of Screen and Digital Printing Technologies. This international group of experts honors individuals who have made outstanding, long-term contributions and applied and promoted screen and digital printing and related imaging technologies.