The Basics of DTF Film Coating
DTF printing technology uses specially coated films as a medium for transferring designs onto fabric or other materials. The coating is a “tool” that both absorbs and releases the ink. In order to print, the coating must perform both functions.
DTF film is a PET (polyethylene terephthalate) sheet with a coating layer that receives ink and adhesive powder. Once these printed designs are heat-pressed onto a surface, such as a T-shirt or a tote bag, they are bonded together to display the design on these objects.
Why Is the Coating Important?
The coating ensures proper ink adhesion and smooth heat transfer. If the coating is subpar, the ink may smudge, the design could peel, or the overall print quality will drop dramatically. High-grade coatings, on the other hand, help preserve color vibrancy, create crisp outlines, and maintain the longevity of the printed design.
DTF Film Coating: Differences Between Single-Sided and Double-Sided
The so-called single-sided and double-sided are additions or subtractions in the film coating, and a single side will have one less coating than a double side. As a result, certain advantages are missing in actual printing.
The first layer is the release layer: mainly to control the peeling is also is often referred to as the cold tear hot tear and second tear.
The second layer is the ink-absorbing layer: mainly to control the ink-absorbing performance of color reproduction.
Double-sided film back coated with a layer of anti-slip and de-static coating.
Summarize: conventional double-sided film will be more than single-sided film baked once his ink absorption performance will be higher than the single-sided film will be 5% -10%.
If you need to know how the film is used, see: DTF Transfer Film Sheets How To Use?
Common DTF Film Coating Structures
To understand how DTF film works, it is important to first understand what structures it has. Films made by different manufacturers will vary, but standard films generally include these coating structures.
- Release Layer (Heat/Cold Release): This layer allows you to peel the film off without damaging your design. Depending on the film, it’s formulated for hot peel, cold peel, or a specialized peel.
- Ink-Absorbing Layer: This coating is capable of both absorbing and releasing ink. Absorption helps retain the ink and affects the vibrancy of the design. Release requires high temperatures; the ability to release absorbed ink while maintaining resistance to bleeding or fading is critical for achieving high-resolution printing.
- Adhesive Layer: This adhesive layer is responsible for adhering the printed design to the fabric and activates when heat is applied, ensuring that the ink layer is smoothly bonded to the material. The ability to bond and release the ink are not the same, so two coatings are needed to achieve this.
- Base PET Film: Serving as a sturdy substrate, PET film is more durable and less likely to warp compared to standard paper. It provides a stable foundation for the layers above.
- Optional Antistatic Layer: Some DTF films, particularly double-sided ones, include an antistatic coating to prevent static build-up and ensure minimal disruption during printing or storage.
For more ways to store it, you can refer to this article: DTF Films Storage Guide.
How to Identify DTF Film Coating
Since DTF films typically have a coated side (for printing) and an uncoated side, figuring out which side to print on can save you a lot of frustration.
Coated vs. Uncoated
- Coated Side:
- Appears slightly matte or less glossy.
- Feels a bit rough to the touch.
- Formulated to hold ink and adhesive powder effectively.
- Uncoated Side:
- Smoother and glossier.
- Will lead to smudging, poor adhesion, and reduced image clarity if used for printing.
Quick to Identify the Coated Side
- Visual Inspection: Compare both sides under good lighting. The coated side usually looks more matte or textured.
- Touch: Run your fingertips over the surface. The coated side should have a faintly rough feel.
- Water Test: Sprinkle a few drops of water on both sides. The coated side may absorb or slightly spread the water, whereas the uncoated side will repel it more readily.
- Check Manufacturer’s Guidelines: Many rolls come with instructions or markings on the packaging. Always confirm with your supplier to avoid confusion.
If you want to know how to judge the quality of DTF film, you can refer to: How to Determine The Quality of DTF PET Film?
The Role of Coating Beyond DTF: Artificial Coating
In the larger printing world, “manual” coating is the process of applying a thin layer of functional material to a web, film, foil or fabric. You can think of it as manually giving certain materials a coating.
- Efficiency and Scale: Suitable for mass production, especially for projects that require uniform and consistent printing results.
- Versatility: In addition to fabrics, it can also be used in a variety of industries such as printing, packaging and electronics.
Coatings in general can be decorative, protective, or both. The formulation often involves resins (or binders), solvents (possibly water), pigments, and various additives. As technology evolves, efforts continue to eliminate harmful substances (like heavy metals) from coating formulas.
Double-Sided vs. Single-Sided: A Market Perspective
As DTF technology has evolved, many suppliers offer both single-sided and double-sided films. One significant difference is that double-sided films typically include an additional anti-slip and anti-static coating on the back side, which helps minimize printer head clogging or misalignment. Additionally, double-sided films offer a 5%-10% increase in ink absorption compared to single-sided films.
In the future, cost considerations and market demands might lead to single-coat approaches or hybrid formulas, but for now, the industry offers a range of coating variations to suit different printing requirements.
Conclusion
The DTF film coating is more than just a protective layer, it is a carefully designed structure that ensures that every design you transfer looks good.
When you know how to identify the coated side and select a film tailored to your design’s complexity and production volume, you’ll significantly reduce errors and waste. This knowledge empowers you to deliver professional-grade results every time, whether you’re a hobbyist exploring new designs or a business owner scaling up your custom apparel line.