Soft gradients, glows and semi-transparent pixels often print badly on shirts because DTF, and DTG on dark garments, put a white base under the colour, and that base does not fade out the way pixels fade on your screen: the soft part turns into a hard edge, a patchy fade or a faint box around the design. Halftone printing fixes this by turning each tone into solid dots of different sizes or spacing, which the printer reproduces cleanly and the eye blends back into a smooth fade.
This matters most if your designs use vintage fades, distressed textures, soft shadows, watercolour edges or photos, and if you sell them on dark shirts. It is also for anyone whose sample came back with a grey rectangle behind the artwork, which is a common sign of stray transparency in the file.
Why transparency is the real problem
A PNG pixel can be fully transparent, fully opaque or anything in between, and your screen blends the in-between pixels smoothly with whatever sits behind them. A print has no such blend built in. Each spot on the shirt either gets ink or it does not, and on a dark shirt it also either gets a white base or it does not.
In DTF, the design is printed onto a special film, coated with adhesive powder and heat-pressed onto the garment (Printify: DTF vs DTG), and a white ink layer on the film lets the transfer work on any fabric colour (Printify Help: print methods). A pixel that is only partly opaque still needs film, white and glue behind it, so it tends to print as a pale, solid patch instead of a soft fade. In DTG, dark garments need "a pretreatment coat and a white ink underbase", and Printful describes gradients as "tricky to print" on black or colourful garments (Printful: DTG vs DTF).
How a printer treats in-between pixels depends on the machine and the provider's settings, so the same file can come out differently at two print shops. Removing the doubt from the file is safer than hoping the printer guesses what you meant.
What a halftone does
A halftone replaces a smooth tone with a pattern of fully opaque dots. Where the tone is strong, the dots are large or packed close together. Where it fades, they shrink or spread out, and the shirt colour shows through the gaps. At normal viewing distance the eye mixes dots and fabric into a gradient, the same trick newspapers and screen printers have relied on for a long time.
There are two common kinds. Amplitude-modulated halftones keep a regular grid and change the dot size, which gives the classic round-dot or line look. Frequency-modulated halftones (often called diffusion or stochastic) keep the dots the same size and change how many there are, which looks more like grain. Both leave the printer nothing but solid pixels.
Dot size matters on fabric. Very fine dots can fill in, smear or drop out on a textured shirt, while coarser dots survive and become part of the look. Your provider can tell you the smallest detail their process holds. Our guide to thin lines and small text covers the same limit for lettering.
Which design elements need attention
| Element | What can happen in print | Safer approach |
|---|---|---|
| Gradient between two solid colours | Usually prints well, since every pixel is opaque | Keep it and check it on a sample |
| Fade into transparency | Hard edge, patchy fade or a pale box | Halftone the fade, or end it in a solid colour |
| Soft drop shadow | Grey cloud or rectangle around the art | Remove it, or use a hard offset shadow |
| Outer glow | Pale halo on dark shirts | Replace it with a solid outline |
| Feathered or blurred edges | Fuzzy, uneven border | Clean the edge to full opacity |
| Low-opacity texture or distress | Specks that print solid or vanish | Turn them into fully opaque specks |
| Photo with a soft background | Visible box around the subject | Remove the background cleanly |
DTF and DTG handle fades differently
DTF prints on almost anything: it "can print on cotton, polyester, nylon, and blends alike" (Printify: DTF vs DTG). Because every printed area becomes "a thin, smooth layer you can feel sitting on top of the fabric", halftones bring a second benefit: a large area broken into dots puts less film on the shirt. Printful notes that the breathability of DTF prints "is relatively low" (Printful Help: print methods), so a halftoned background can make a big print lighter to wear. Our explainer on what DTF printing is covers the process step by step.
DTG sprays water-based ink that "absorbs into the fibers, so the print feels part of the shirt." On white and light shirts DTG skips the pretreatment and white underbase, so soft colour transitions are less risky there. On dark shirts the underbase comes back, and so do the fade problems. If you sell one design on light and dark garments, plan the dark version separately: our article on printing on dark garments explains the underbase, and what DTG printing is covers when DTG is the better choice.
Preparing a file that prints the way it looks
Export a transparent PNG at the print size, never a JPEG: JPEG has no transparency, so transparent areas can print as white (Printful Help: file guidelines). Our print file requirements list the rest.
Work at 300 DPI at the real print size, the resolution Printify recommends for PNG files (Printify Help: file requirements).
Zoom in on edges, shadows and textures, and find every semi-transparent pixel you did not mean to keep.
Decide fade by fade: halftone it, end it in a solid colour, or remove it.
Preview the design on every shirt colour you will sell, and order a sample of anything built on heavy fades.
How Alomations handles the cleanup
Our catalog apparel is printed with DTF (catalog), so transparency is something every design has to get right. Designs come back print-ready at 12 inches and 300 DPI (3,600 pixels on the long side), as a transparent PNG with an SVG alongside. On paid plans, the Design Editor has the tools for the cleanup this article describes: one-click background removal for photos with soft backgrounds, an eraser on image layers for stray edges, outlines to replace glows, and redrawing flat art as vector for crisp edges.
Light and dark versions come from one design, and tone rules per garment colour decide which version each shirt colour gets, so the fades on a dark shirt can be handled apart from the light ones. For designs built on soft fades, still order a sample before you list them widely.
Frequently asked questions
Can DTF print gradients at all?
Yes. A gradient between two solid colours prints well because every pixel is opaque. The trouble starts when a gradient fades into transparency, and that is where a halftone helps.
Do halftones make a design look worse?
Coarse halftones are visible up close, and many vintage and retro designs use them on purpose. Finer halftones read as a smooth fade at normal viewing distance, as long as the dots are big enough for the print process to hold.
Do I need halftones for white shirts?
Less often. DTG on light garments skips the white underbase, so soft fades are less risky. DTF transfers usually carry a white layer on any shirt, so fades into transparency are still worth halftoning for DTF, even on white.
Should I halftone a photo?
On dark shirts it often helps, because the background and soft edges are where photo prints fail. Remove the background first, then decide whether the remaining soft areas need dots, and ask your provider whether they convert photos for you.
You can see the print-ready files a run delivers by trying Alomations on the free plan.