DTF transfer printing — what the file and the press each have to carry
Direct-to-film sits between two limits. One belongs to the press: heat, time and the smallest detail a transfer can physically hold. The other belongs to the file that arrived in a chat window. Most shop-floor arguments come from treating a file problem as a press problem, or the reverse, so both sets of numbers are worth keeping in one place.
| Transfer film, sheet format | A3 — 29.7 cm / 11.7 in usable width |
|---|---|
| Transfer film, roll format | 30 and 60 cm rolls are the common shop sizes |
| Press temperature | 150-165 °C / 300-330 °F |
| Press time and pressure | 10-15 seconds, medium pressure |
| Peel | film-dependent — hot peel after about 5 s, cold peel below 40 °C |
| Second press after peeling | 5-8 s through parchment, for hand feel and wash durability |
| Smallest text height that stays open on textile | about 4 mm / 0.16 in at print size |
| Smallest stroke that survives the transfer | about 0.5-0.75 mm |
| Resolution band that holds on cotton | 200-300 DPI measured at the size being printed |
| File the press wants | transparent PNG or vector — the white underbase is generated, not drawn |
What the fabric forgives, and what it will not
Cotton scatters light, so a textile print hides softness that the same file would expose on paper. That tolerance is real and it is where the 200 DPI floor comes from. It does not extend to geometry: a hairline thinner than the transfer can hold breaks up regardless of resolution, and a letterform below roughly 4 mm closes into a blob whether the file was 300 DPI or 3000.
- Softness — largely hidden by the weave
- Thin strokes and small counters — not hidden, they simply drop out
- Halos and hard compression edges — more visible on textile, not less
The order the decisions come in
Every job below runs the same sequence, and the expensive mistakes come from jumping a step. Measuring after the blank is loaded costs a blank; asking the customer for a better file after the press is hot costs the slot as well.
- Measure the file — pixel width, edges, transparency, any text
- Decide the size — the width those pixels cover is a number, not an opinion
- Repair only what can be verified afterwards, and keep the original
- Press to the numbers above, then peel by the film's rule rather than by habit
Where files fail before the press ever runs
The guides under this page each cover one failure that arrives with the artwork rather than with the equipment. They carry their own measurements: pixel thresholds per placement, what each messaging app does to a file, and what the shop should charge or refund when the file cannot be saved.
FAQ
- Does DTF need 300 DPI?
- 300 DPI at final print size is the working target. Because the weave hides some softness, 200-300 DPI passes on most jobs; below 150 DPI the softness is visible on the garment at arm's length. The number that matters is measured at the size being printed, not the one written in the file's metadata.
- Why does small text look fine on screen and close up on the shirt?
- A monitor shows roughly 72-160 pixels per inch and has no ink spread. The transfer has a physical floor: below about 4 mm of letter height the gaps inside letters fill in. Zooming in on screen removes the exact constraint the garment imposes.
- Does a vector file remove every limit?
- It removes the pixel ceiling — scale stops mattering to resolution. The physical floors stay: stroke width, text height and how much detail the film can hold do not change with scale, and gradients inside a vector rasterise on export and carry a resolution again.
- Work out the width a file covers before quoting a size
- A customer sent a blurry logo — how wide it can still go
- The file is a screenshot, not the artwork
- Asking for a better file, in wording that gets an answer
- Deciding whether a file survives the requested print size
- Pricing artwork repair from a designer hour
- Reprint or refund once a complaint arrives
- Where the automated repair will live
- The seven checks, in the order that settles files fastest
- Why the number in the file header decides nothing
- Choosing the export before the design is finished
- What enlarging a file adds, and what it cannot
- When a background cannot be separated cleanly
- The pale rim a cut-out leaves on dark fabric
- Telling a real cut-out from one that only looks cut out
- Compression damage that resizing cannot undo
- Three causes of a rough outline, three responses
- The height below which lettering closes up
- What each format settles before printing
- Checking a file that arrived in a conversation