DTF and UV DTF printing glossary

DTF and UV DTF printing terms

Every entry stands on its own: you can read one without having read the ones before it.

DTF Direct to Film

Printing onto a film that is then transferred to the garment with heat. You print the colour, apply adhesive powder, cure it and press the design onto the fabric. Unlike screen printing it needs no screens, so it pays off from a single unit.

RIP Raster Image Processor

The program that translates a design file into something the printer can actually print: how much of each ink lands on every dot, where the white goes and in what order the passes run. A DTF printer does not understand a JPG or a PDF; it understands what the RIP sends it.

PRN

The file the printer's board reads directly, with the ink already distributed dot by dot. It is not an image: it is the firing instruction for the printheads. Sapiens CoreFlow RIP writes the native PRN for BYHX and HOSON boards, with no intermediate driver.

BYHX

One of the two most widespread boards in DTF printers. It controls the printheads and the film feed, and comes with its own Print Manager. Sapiens CoreFlow RIP generates the PRN with a native BYHX header, which is what avoids conversions along the way.

HOSON

The other common board in DTF. It works through a watched folder: the board picks up files that appear in a folder and prints them. Sapiens CoreFlow RIP writes that format directly, so the workflow is the same as with BYHX even though the output file differs.

ΔE Delta E

The measure of how far apart two colours are to the human eye. A ΔE below 1 is indistinguishable; below 2 is considered professional accuracy, and it is the target Sapiens CoreFlow RIP is profiled against. The higher it goes, the more obvious it is that the print is not the colour that was asked for.

ICC profile

The file describing how a specific device reproduces colour. It works as a translator: it says which ink mix produces a given colour on that machine, with that ink and that film. Without a profile, the RIP is guessing.

Linearisation

The adjustment that makes a 10% increase in ink produce a 10% increase in printed density. Without it the machine responds in jumps: midtones bunch up and gradients come out banded. It is the mandatory step before building an ICC profile.

Halftoning

Distributing ink as dots to simulate continuous tones with a limited number of levels. A printhead can only fire or not fire; halftoning decides where those firings land so the eye sees a gradient instead of a grid.

Channel separation

Converting the RGB design into the channels the machine actually prints: cyan, magenta, yellow, black, white and, in UV DTF, varnish. This is where you decide how much black replaces the colour mix and how much total ink lands, which is what drives cost and drying.

Underbase backing white

The layer of white ink that goes under the colour so the design does not show through on dark garments. In Sapiens CoreFlow RIP it is calculated from the image itself: where there is colour there is white, and where the file is transparent no ink lands.

Choke

Shrinking the white layer slightly relative to the colour so no white edge peeks out around the design. It compensates for the small mechanical offset between passes, and is measured in pixels or tenths of a millimetre.

TAC Total Area Coverage · total ink limit

The maximum ink allowed on one dot across all channels combined. Going over floods the film, lengthens drying and stops the adhesive powder from sticking evenly. Going too low dulls blacks and saturated colours.

GCR and UCR

Two ways of replacing the grey part of a cyan, magenta and yellow mix with black. They cut ink, stabilise neutrals and stop greys from drifting in hue. GCR replaces across the whole range; UCR mainly in the shadows.

Gamut

The set of colours a specific combination of machine, ink and film can actually reproduce. Design colours that fall outside the gamut cannot be printed as they are: they have to be moved to the nearest match, and that is where a good RIP shows.

Spectrophotometer

The instrument that measures printed colour so it can be corrected with data instead of by eye. Sapiens CoreFlow RIP is integrated with the X-Rite i1Pro 2, both for single patches and for full charts in strip mode.

Gang sheet

The sheet where many designs are laid out together to make use of the full roll width. The better the imposition, the less film is wasted. In real production this is where the margin on a job is won or lost.

DTF film

The PET sheet printed on before transferring to the garment. Its coating determines how much ink it takes and how the design releases when pressed, so a colour profile built for one film does not simply carry over to another.

Adhesive powder hot melt

The heat-activated powder applied over still-wet ink and then cured. It is what bonds the design to the fabric during pressing. If the print carries too much ink, the powder does not stick evenly.

UV DTF

Printing with UV-cured inks onto a film that transfers to rigid surfaces: glass, metal, plastic or cardboard. It needs no heat and no press and, unlike textile DTF, it does not go onto a garment.

UV DTF 3D

UV DTF with real relief: layers of varnish built up over the design until the texture can be felt. Height comes from the layers and the pattern is defined by the applied texture. It is the dedicated mode in Sapiens CoreFlow RIP.

Varnish channel

The channel that prints clear varnish, separate from the colour channels and from white. It is used for selective gloss, matte by area or relief. In Sapiens CoreFlow RIP it is the sixth channel of the PRN and is enabled per machine profile.

Print & cut

A workflow where you print first and then cut the contour of each piece. It requires the cutter to locate the printed design precisely, which is what registration marks are for. Sapiens CoreFlow RIP generates the cut file from the same job.

Registration marks

The printed marks a cutter reads with its optical sensor to know exactly where the design ended up on the material. Without them the cut drifts, because the film never enters the cutter in exactly the same position.

Bleed

The margin of design left outside the cut line so that, if the cut drifts slightly, no unprinted edge appears. In contour cutting it is measured in millimetres around the silhouette.

Hotfolder watched folder

A folder the program watches: every file that appears inside is processed on its own, using the settings saved for that folder. It is how you run batches without opening jobs one by one. In Sapiens CoreFlow RIP these are the Quick Print Sets.

Preflight

The check that warns you what is going to go wrong before you spend film: too much ink, colours outside gamut, insufficient resolution or badly calculated white. Sapiens CoreFlow RIP runs it on the rasterised pixels, not on the source file.

Epson I3200-A1

The printhead fitted to most current DTF printers. It determines how many channels are available, the resolution and the speed. Machines are configured with one, two or four heads depending on the output they have to deliver.

Passes

The number of times the head travels over the same strip of film. More passes give more density and hide nozzle defects, but cut speed. It is the setting that most directly trades quality against output.

Dot gain

The printed dot always comes out larger than calculated, because ink spreads on the film. If it is not compensated, everything prints darker than intended. Linearisation and the ICC profile are what correct that difference.

Is a term missing?

This glossary comes from the questions we actually get, not from a manual. If you have run into a word that is not here, write to us and we will add it: chances are ten other printers are wondering the same thing.