DTF, DTG, sublimation and heat transfer

Four newer processes, four different files

Screen printing is not the only way to get a design onto fabric, and the alternatives have different economics and different file requirements. Knowing which is which lets you advise a client rather than repeat what the last shop told them.

DTG: direct to garment

An inkjet printer that prints water-based ink directly into the fabric.

• Cotton only, or high-cotton blends. Ink does not bond to polyester.
• On dark garments, a white underbase is printed by the machine after a pre-treatment liquid is applied and heat-pressed. The pre-treatment is essential and shows as a faint square if applied unevenly.
• No setup cost, so a run of one is viable. Per-unit cost is high, so a run of 500 is not.
• Full colour, photographic, no colour limit.
• File: a high-resolution raster (300 ppi at final size) with a genuine transparent background. Vector is fine as a source; the RIP rasterises it.

Soft hand-feel, excellent detail, limited to cotton, fades faster than screen print.

DTF: direct to film

Currently the process spreading fastest in small shops. The design is printed onto a PET film with white ink behind it, powdered with an adhesive, cured, and heat-pressed onto the garment.

• Works on almost anything: cotton, polyester, blends, nylon, leather, dark or light.
• No pre-treatment, no cutting, no weeding.
• Full colour, and the white is printed automatically as a backing layer.
• File: raster at 300 ppi with true transparency, or vector. The RIP generates the white layer from the alpha channel, so the transparency must be clean: a soft feathered edge produces a visible white fringe. Hard edges, or a deliberate 1 px feather at most.
• Sits on top of the fabric as a film, so the hand-feel is plasticky compared with screen or DTG, and a large solid area is noticeably stiff.

For short runs of mixed garments, it has largely displaced everything else.

Sublimation

Ink is printed onto transfer paper, then heat and pressure turn it into a gas that bonds into the polymer fibres.

Two hard constraints, and they are absolute:

• Polyester only, or a polymer-coated surface (mugs, phone cases, metal plates, coated MDF). It will not work on cotton at all.
• White or very light substrate only. There is no white sublimation ink, so the substrate provides the white and you cannot print light on dark.

Within those limits it is excellent: the ink is in the fibres, so there is no hand-feel at all, and it does not crack or peel. All-over printed sportswear is sublimation.

File: full-colour raster, and the image must be mirrored before printing, because it is applied face down.

Heat transfer vinyl (HTV)

Cut vinyl, weeded, heat-pressed. Covered in the vinyl lesson, and the two things to remember here are that it is cut mirrored and that it is limited to flat spot colours, which makes it ideal for names and numbers on sports kit and poor for anything detailed.

Choosing between them

• Run of 1 to 20, full colour, mixed garment types: DTF.
• Run of 1 to 20, cotton, soft feel matters: DTG.
• Run of 100+, few colours: screen print, comfortably cheapest per unit.
• Polyester sportswear, all-over or full colour: sublimation.
• Names and numbers, any quantity: HTV.
• Premium feel, few colours, cotton: screen print with a soft-hand or discharge ink.

Two things to tell every client

Ask for a sample before the run. The same artwork looks different in each of these processes, and the difference in hand-feel is something nobody can judge from a photograph.

Wash test it. A sample washed five times tells you more about the process than any specification sheet. DTF peeling at the corners, DTG fading, sublimation ghosting on a poly-cotton blend: all show up in the wash and not before.

What to supply, in one line each

• DTG: 300 ppi PNG at final size, transparent background, sRGB, cotton confirmed.
• DTF: 300 ppi PNG at final size, hard-edged transparency, no feathering beyond a pixel.
• Sublimation: 300 ppi at final size, mirrored, and confirm the substrate is polyester or polymer-coated.
• HTV: vector, mirrored, strokes outlined, overlaps welded, nothing under 2 mm.
• Screen: separations on named layers, 1200 dpi films, underbase choked.

Put the process in the filename. acme-tee-DTF-260x200mm.png tells the shop everything before they open it, and it stops a sublimation file being pressed onto a cotton shirt, which is a mistake somebody makes every week.