How to prepare a file for DTFlex printing: Complete guide

Direct-to-film (DTF) printing was developed to address the limitations of direct-to-garment (DTG) printing, namely, material compatibility and color vibrancy. It first gained traction around the 2000s and has since grown massively in popularity.

Source: Google Trends

The biggest advantages of using the DTFlex – Printiful’s premium direct-to film solution – for custom clothing are the longevity, vibrancy, and crispness of the prints and the huge range of fabrics it can be used on. 

This article will provide insights into DTFlex printing, clear instructions on preparing the print files, and common mistakes to avoid.

Let’s get into it.

What’s DTFlex printing?

DTFlex is Printful’s premium take on direct-to-film printing. Refined for on-demand consistency, it uses water-based inks and a proprietary adhesive process to deliver vibrant, durable designs with flawless edges across a variety of fabrics.

Source: Printful

Valuable read: What You Need to Know about Direct-to-Film Printing

Here’s a real-life example of how we make a DTFlex shirt with print-on-demand.

First, the design is printed onto a special transfer film with water-based inks. Then, the print on the film is coated with a layer of white ink that acts as a binder for the adhesive powder.

Our fulfillment specialist then cuts out the film with your design.

Source: Printful

The film is then applied to the garment and placed under a heat press that transfers the design from the film to the tee.

And, voilà, your shirt’s ready!

Source: Printful

A similar-sounding printing technique, direct-to-garment (DTG), differs from DTFlex printing. What’s the difference between DTG and DTFlex printing? Here’s a 2-minute video explaining both techniques and giving you a behind-the-scenes look.

But wait, there’s more

With DTFlex, Printful has expanded beyond apparel into custom hats, giving you premium-quality prints on structured styles like trucker caps, snapbacks, and rope caps.

Featured DTFlex-compatible hats:

1. 5 Panel Trucker Cap | Yupoong 6006

2. Vintage Cap | Otto Cap 18-1248

3. Foam Trucker Hat | Otto Cap 39-165

4. Golf Rope Cap | Big Accessories BA671

What are the differences between print files for DTG and DTFlex printing?

While there are differences between both techniques, there aren’t many differences between DTG and DTFlex print files. Here are a couple of things you shouldn’t use in your DTFlex designs:

• Small dots and narrow lines as there’s a risk they’ll peel off because of the small area of applied adhesive 

• Gradient transitions from solid to transparent or semi-transparent design elements

• Large prints that cover a lot of the garment (especially if the fabric’s thin) because it will feel plasticky and won’t be breathable

File prep for DTFlex printing: Best practices

Find tips, guidelines, and disclaimers for your files in the File guidelines tab in our Product Catalog.

Source: Printful Catalog

Now, on to the best practices when creating your DTFlex print files. 

Avoid semi-transparent designs

Semi-transparent graphics (or elements with lowered opacity) don’t translate well in direct-to-film printing. We recommend using solid colors.

Have see-through elements in your design

Incorporate see-through elements throughout the design to give your print a lighter feel. This way, less ink and adhesive will be applied to the garment, creating a softer result compared to large, solid-color designs.

Create the designs with the necessary DPI

DPI (dots per inch) is the number of dots in a printed inch. The more dots, the higher the print quality (more sharpness and detail). Simply entering a new resolution value won’t result in a higher-resolution print. If your graphic’s resolution is too low, the best solution is to make a new one. 

Submit files in PNG or JPEG format with 150–300 DPI.

Skip soft edges for designs

Designs with soft edges don’t work for direct-to-film prints because the small ink dots that create the effect don’t have a surface area big enough to adhere to the garment. As a result, you’ll most likely have a rough, blotchy edge.

Customize products with high-resolution images

Direct-to-film printing is a great choice for photography designs as it allows for printing full-color, high-quality images. The higher the image resolution, the clearer and sharper the print result.

Create files in the sRGB color profile

Using the sRGB color profile ensures that the colors in your designs are represented consistently and accurately across different devices, including computer screens and our printers. Extremely bright, saturated colors will become a bit less vibrant due to color print limitations. Using the sRGB IEC61966-2.1 color profile will achieve the best possible accuracy.

Source: Printful

Valuable read: RGB vs. CMYK: Guide to Color Spaces

Here’s a side-by-side visualization of how the design file looks as a print.

Preparing DTFlex print files for hats

When designing for hats, it's crucial to consider the unique contours and seams of each style. To maintain visual integrity, ensure your design fits within the designated print area and avoids critical seams.

Most common mistakes

Knowing what produces poor results can help you create a good design. Knowing what to avoid is as important as knowing what to do. 

So, here’s what our team has seen turn into unsatisfying products:

• Poor print file quality. The DTFlex printing technique is characterized by sharp, crisp lines, so low-quality designs with a resolution lower than 150 DPI can lead to blotchy, uneven edges or unclear prints.

• Too many small details. Small details like dots and thin lines can start peeling off over time because of the thin layer of glue covering the printed parts.

• Huge solid print area. Because the print feels quite stiff, the print covering a large area will result in a garment that’s less breathable and doesn’t look as good.

• Black design on black fabric. Because the black print will look paler or greyer on a black garment, we advise avoiding black-on-black placement.

• Gradient from solid to transparent. The gradient is usually achieved by small dots, and we’ve already covered why you shouldn’t use dots in your designs.

How to take care of your DTFlex printed garments

While DTFlex printing is praised for durability, no print will last if it’s not properly cared for. 

In the case of DTFlex prints, you must:

Wash the garments in cold to lukewarm water

Never put it in hot water—the print will crack

Turn the garment inside out when ironing

That’s it for today

That’s all! We’ve covered everything you need to know about prepping your print file for DTFlex printing when designing staples like custom t-shirts, custom hoodies, or any other garment.

With Printful, you can customize products and order for yourself or start a dropshipping business and earn money with print-on-demand.

If you have any questions or things you’d like us to expand on, leave us a comment below.

Valuable read: 

• What is Print-on-Demand? All Your Questions Answered

• How to Start a Print-on-Demand Business in 2024 in 9 Steps

• How to Start a Clothing Brand in 2024: A Complete Step-by-Step Guide