With its unmatched ability to decorate a wide variety of surfaces, including glass, metal, wood, and plastics, as well as adhering to curved and uniquely shaped items, UV direct-to-film (UV-DTF) printing is a highly sought-after technology for applications ranging from promotional products to interior decor.
As with any print process, to achieve consistent and professional results, it’s essential to follow best practices. We talked with Roland DGA’s Product Manager for Special Devices, Philip Chu, about this popular decorating technology, Roland DG’s Graphic Transfer System (GTS), and his best tips for achieving optimal UV-DTF results.
When is UV-DTF preferred over standard UV printing or a vinyl decal?
UV-DTF is a process for creating a UV-ink printed transferrable decal, which has all the vibrancy and durability benefits of UV printing, but which can be applied to an even greater range of surfaces. Additionally, like with traditional UV printing, UV-DTF’s gloss ink allows you to add surface textures like gloss, matte, or even simulated embossing.
UV-DTF is preferred for several types of applications. The primary one is for applying graphics to nonporous items like glass, where you would normally need an adhesion promoter. Another is for printing on highly reflective surfaces like chrome metallic or mirrored surfaces which can reflect light and cure ink on the printheads leading to more maintenance and repairs.
Another advantage with UV-DTF is that it adheres to just about anything, including curved or uneven surfaces, and to uniquely shaped or oversized objects that might not fit in a standard UV flatbed printer. For example, wrapping around the sides of a square glass jar.
What type of equipment is needed for UV-DTF production?
You need a UV printer, UV inks, and of course print sheets and film. Roland DG offers all of these components in its Graphic Transfer System. For best results and application, we recommend also acquiring a laminator, squeegee, and a heat gun (or hair dryer).
Let’s break this down a little further. First, the UV printer. Because UV-DTF is essentially an “ink sandwich” with white ink on the bottom and gloss ink on top, sealing in your design. Your UV printer needs to be able to print gloss ink. UV-DTF without gloss ink is not recommended because the transfer is very thin and may rip during application.
Roland DG offers a range of UV flatbed printers that fit the bill:
- VersaOBJECT CO-i series wide-format UV printers
- VersaOBJECT MO-240 and MO-180 benchtop UV printers
- VersaSTUDIO BD-8 and BD-12 desktop UV printers with gloss ink
Next, let’s talk about inks. Roland DG’s V-BOND ink is a perfect fit for UV-DTF applications, supplying exceptional image quality, vibrant colors, and excellent scratch resistance. V-BOND inks are also cost-effective, California Prop. 65 certified, and CPSIA/Toy Safety Compliant, ensuring safety and durability.
And finally, print sheets and transfer film. Roland DGA’s Graphic Transfer System includes GTS Print Sheets and GTS Transfer Film, both available at the Roland DGA Store.
Production Tips
When you have the proper tools, producing UV-DTF transfers is easy to do. That said, there are a few things to know that can make the process smoother and more consistent. Here are my tips for production of UV-DTF graphics:
Gang sheets for the win
You can print your transfer designs in bulk on a gang sheet, allowing a space of at least 1/8” around each design. For example, you can print a gang sheet of logos for a Little League team that you apply to items and sell – or, simply sell the transfers themselves.
Pro Tip: You can print your transfers weeks or even months ahead of time, and ship or adhere them later.
Proper positioning for premium production
When preparing to print, remember that once you remove the cover sheet, the remaining surface area is exposed adhesive, except for a ½ inch area on the top and bottom of the transfer paper.
Pro Tip: Touch only that ½ inch area to position your sheet in the printer. You can use masking or double-sided tape to secure the corners of your paper to the vacuum table.
After you have printed your transfers, they need to be laminated with the film transfer sheet. This will protect your printed transfers and seal in the exposed (non-printed) adhesive. A heated laminator is recommended for this step, as the rollers create consistent pressure across the width of your sheet.
This may be where you stop if you are sending UV-DTF transfers to your clients for application. If so, you may want to encourage them to follow the application guidelines below. If you are applying the transfers yourself, you’ll want to pay attention to the points below.
Application Tips
Allow for curing time
Wait 1-2 hours or even overnight after printing to be sure the inks are fully cured. This additional drying time will ensure the transfer is set up and ready to apply to your item.
Pro Tip: Incorporating curing time is easy if you are shipping your transfers overnight – they will be dry and ready to apply by the time they are received.
Clean and dry your item before applying your transfer
Dust or films can affect the adhesion of your transfer, so be sure the surface of the item you will be applying the transfer to is clean and dry.
Pro Tip: Wipe the surface you are applying to with 91% isopropyl alcohol or denatured alcohol and allow it to dry before applying your transfer. This will keep your items free of dust and chemicals (like oil from your fingers).
Double burnish your cylindrical or spherical items
For cylindrical or spherical items, we recommend using a double burnish application workflow that includes the following steps:
- Apply your UV-DTF graphic to your item, then use a squeegee to smooth it on.
- Follow that by lightly passing a heat gun over the graphic a few times.
- Then use your squeegee one more time to smooth the graphic.
- Peel the transfer tape away slowly.
- Use isopropyl alcohol to wipe away any remaining glue.
This process ensures a clean transfer when you pull off the transfer film. Most of the spare glue ends will have been removed, and your clean up after application will be much easier.
Give yourself a hand
If you are applying your UV-DTF design to cylindrical or round items such as tumblers or cups, having a “third hand” can come in, well, handy! Using a fixture or “jig” keeps these types of items steady and frees your hands to apply the transfer.
Pro Tip: Consider purchasing an inexpensive jig online, fashioning one out of Styrofoam, or even 3D printing a jig.
Following these guidelines will help you consistently produce high-quality, vibrant UV-DTF transfers with good adhesion and durability.
For additional details, please see our Roland TV step-by-step DTF production workflow videos and the “Best Practice Workflow for GTS” blog.
For information on Roland DG’s line of UV flatbed printers, visit https://www.rolanddga.com/products/printers/versauv. To learn more about the Roland DG Graphic Transfer System, click here.
