How we print
A cotton shirt, a ceramic mug and a fleece blanket each call for a different way of printing. Ink has to bond with whatever lies underneath, and that works differently every time for cotton, ceramic and polyester. Here you can read, product by product, which technique we use, what happens during printing and what that means for your design, your photo and how long your gift will last.
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Three materials, three techniques
Cotton is a plant fibre that absorbs moisture. Water-based ink soaks into it, and heat cures a binder that anchors the pigment in the fibre. Polyester is a synthetic that doesn't absorb water, but at high temperatures its fibres open up and take in dye that arrives as a gas. Ceramic absorbs nothing at all, because the glaze is glass. That's why a mug gets a thin polymer layer that the same dye can soak into, just as it does with polyester.
So there is no technique that works equally well on everything. Sublimation on cotton washes out after a few washes, and textile ink won't stick to smooth ceramic. For each product we choose the technique that suits the material.
| Technique | Products | Material | Where the ink sits | Colour | Care |
|---|---|---|---|---|---|
| Direct-to-garment printing (DTG) | T-shirts, sweaters, hoodies, bodysuits | Cotton or cotton-rich fabric | In the fibres, set with heat | All colours, white via an underbase | Inside out, cold wash |
| Sublimation | Mugs | Ceramic with a polymer coating | In the coating | All colours except white: white is the mug itself | Dishwasher safe, a magic mug by hand |
| Edge-to-edge sublimation | Blankets, doormats | Polyester | In the fibre itself | Very bright, white is the fabric itself | Follow the care label, the colour won't run |
Direct-to-garment printing (DTG)
DTG stands for direct to garment: a textile printer works like an inkjet printer, but sprays the ink straight into the fabric instead of onto paper. No film, transfer or plastic layer is involved.
- Water-based colour ink, in cyan, magenta, yellow and black
- White underbase, only on coloured fabric
- Pretreatment, which keeps the ink at the surface
- Cotton fibres, in cross-section
How it works
- Pretreatment. On a coloured shirt, a thin liquid is first applied where the print will go. It keeps the white ink at the surface instead of letting it sink in between the fibres. A white shirt doesn't need this.
- The white underbase. Water-based ink is translucent, just like watercolour paint. On dark fabric your design would look dull, so the printer first lays down white beneath everything that needs to be light or coloured. On a white shirt, the fabric itself is the white.
- Colour. The print head sprays cyan, magenta, yellow and black into the fibres in thousands of tiny droplets. That makes photos, colour gradients and fine lines possible, even when your design has dozens of colours.
- Setting. A heat press warms the print to around 160 °C. The binder in the ink cures and anchors the pigment in the fibre. Only then is the print washable.
How long it lasts
Because the ink is in the cotton rather than on it, it can't crack or come loose like an ironed-on transfer. It wears along with the fabric: after a great many washes it becomes a touch softer in colour, like a well-washed pair of jeans. Wash your shirt inside out on a cold cycle, don't tumble dry on a high setting and don't iron over the print. Our ink carries the OEKO-TEX and GOTS labels: tested for harmful substances.
What this means for a design
The white underbase is the reason our designers avoid semi-transparent areas on dark shirts: anything semi-transparent gets less ink, and then the white shows through. Lines are at least one and a half millimetres thick, so they stay sharp in the fabric too. A photo prints most true to life on a white or light shirt; on a black shirt the dark parts of the photo barely show, because there the fabric itself is the black.
Sublimation
Sublimation is the moment a solid turns straight into a gas, without becoming liquid first. With this technique that happens to the ink: it evaporates from the paper and soaks into the mug's coating as a gas.
- Transfer paper with your design in mirror image
- Ink that turns into a gas in the heat
- Polymer coating, in which the ink becomes trapped
- Ceramic
How it works
- Printing on paper. Your design is printed in mirror image with sublimation ink on transfer paper.
- Around the mug. The paper is wrapped tightly around the mug, with the ink facing the surface.
- Heating. In a mug press, the mug is heated to 180 to 200 °C for a few minutes. The ink turns into a gas, the coating opens up and absorbs the gas.
- Cooling. The coating closes again and the ink is locked inside. The paper comes off, and what remains is a smooth surface with your design inside it.
How long it lasts
Your design doesn't sit on the mug but inside the top layer itself. Run your finger over it: you won't feel an edge, just smooth ceramic. There's nothing that can peel or come loose, and the mug is dishwasher safe. The colours stay bright. A magic mug has an extra heat-sensitive layer over the print; that one you wash by hand.
What this means for a design
Sublimation ink is translucent and there is no such thing as white sublimation ink. Everything that's white in your design is the white mug itself. Because the ink soaks in as a gas, colours blend smoothly into one another, and that's why photos with soft transitions look so good on a mug.
Edge-to-edge sublimation
The same technique as on a mug, but on polyester and across the whole surface. Here the ink colours the fibre itself, from the inside: nothing sits on top, so a throw stays just as soft as it was before printing.
- Transfer paper with your design in mirror image
- Ink that turns into a gas in the heat
- Polyester pile fibres, coloured from the inside
- The backing fabric that holds the pile
How it works
- Printing on paper. The whole surface is printed in mirror image on a roll of transfer paper, right over the edge.
- Pressing. Paper and fabric go through a large heat press together, at around 200 °C. The pores of the polyester open and the ink soaks into the fibres as a gas.
- Cooling. The fibres close and the colour is locked inside.
- Finishing. The blanket is then finished to size. A few centimetres along the edge disappear into the hem.
How long it lasts
Because the colour is in the fibre, it can't wash out or flake off. The colours stay bright, even after many washes. Follow the care instructions for the product; they're about the fabric, not the print.
What this means for a design
Here too there's no white ink: white in your design is the white fabric. Don't put anything important right up against the edge, because that part may end up in the hem. And large solid dark areas need a lot of ink in one spot, which makes the pile a touch stiffer. That's why a lighter background is often the better choice on a blanket.
Why not screen printing, DTF or transfers?
There are more ways to print something, and each has its own strengths. Most are made for large runs of the same design, or for a different kind of image than a photo with a name. For a single personalised piece they're a poorer fit.
| Technique | How it works | Good at | Why not for a personalised gift |
|---|---|---|---|
| Screen printing | Ink is pushed through a fine mesh onto the fabric, with a separate mesh for each colour. | Thick, vivid and very durable areas of colour, good value for large runs. | Every colour needs its own screen and setup time, so it only pays off from dozens of copies of the same design. Photos and soft gradients don't come out well. |
| DTF (direct to film) | The design is printed on a film, given an adhesive powder and pressed onto the fabric with heat. | Works on almost any fabric, including polyester and nylon, with vivid colours. | The print sits on the fabric as a thin layer instead of in it. You can feel that on large areas, and there the fabric breathes less. |
| Flex and flock | Letters and shapes are cut from a sheet of coloured film or velvet and ironed on. | Names and numbers in a single colour, as on sports shirts. | No photos and no gradients; every colour is a separate layer, and over time the edges can come loose. |
| Embroidery | The design is stitched into the fabric with thread. | A raised logo or monogram, practically indestructible. | No photos or fine details, and every design first has to be mapped out stitch by stitch. |
| Kiln-fired decal | A design on transfer paper is placed on a mug and fired into the glaze in a kiln. | Mugs in large series, with a print as hard as the glaze. | Firing takes hours and only pays off for large numbers of the same design. |
| UV printing | Ink is sprayed onto the surface and instantly cured with UV light. | Almost any hard material, from wood to phone cases. | The ink sits on the surface instead of in it, which makes it more sensitive to scratches and the dishwasher. |
From screen to print
Resolution: enough pixels for the size
- Too few pixels for the size: a round edge turns into a staircase of blocks.
- Enough pixels: the same edge prints smoothly.
A printer doesn't count in pixels but in dots per inch (dpi), at the actual size of the print. For something you look at up close, like a mug or a shirt, 300 dpi is the standard. A blanket is seen from further away, so 150 dpi is enough. In pixels, that works out roughly as follows:
- the print area of a mug, 19 by 8.5 cm: 2,250 by 1,000 pixels
- a full shirt front, 30 by 40 cm: 3,550 by 4,700 pixels
- a blanket of 150 by 200 cm: almost 9,000 by 12,000 pixels
A recent 12-megapixel phone photo is 4,000 by 3,000 pixels: plenty for a mug and for a shirt. On a large blanket a photo is enlarged, and because you look at a blanket from a distance, you won't notice. If you also have the same photo as the original, choose that one: WhatsApp and social media shrink photos when they're sent.
Colour: light versus ink
- A screen mixes light: red, green and blue together make white (RGB).
- A printer mixes ink: cyan, magenta and yellow together make almost black, which is why real black ink is added (CMYK).
Your screen creates colour by emitting light, a printer with ink that absorbs part of the light. The two can't make exactly the same colours. Before printing, the colours of your design are converted with a colour profile to what the printer and the material can handle. Very bright screen colours, such as neon green, electric blue or fluorescent pink, don't exist in ink and come out a little calmer.
The material matters too. Cotton absorbs ink and shows colours softer and more matte, while a coated mug keeps them glossy and saturated. And not every screen shows the same thing: a phone at full brightness makes a photo look brighter than it really is.
Printing glossary
- Bleed
- A strip of the design that runs just past the edge of the finished product, so that no white edge appears after cutting or sewing.
- CMYK
- Cyan, magenta, yellow and black: the four ink colours from which a printer mixes every other colour. The K stands for key, the black printing plate.
- Colour profile
- A table that describes which colours a printer can produce on a particular material, and which is used to convert the colours of your design accordingly.
- Dpi
- Dots per inch, the number of dots per 2.54 cm at the actual size of the print. 300 dpi is the standard for anything you look at up close.
- DTG
- Direct to garment, or direct textile printing: a printer sprays ink straight into the fabric.
- Pigment ink
- Ink with solid, tiny colour particles that are fixed to the fibre with a binder. Used for DTG.
- Polymer coating
- A thin plastic layer on a mug or other hard material, into which sublimation ink can soak.
- Pretreatment
- A liquid applied to coloured fabric before DTG, so that the white underbase stays at the surface.
- Print area
- The part of a product that can be printed, such as 30 by 40 cm on the front of a shirt.
- RGB
- Red, green and blue: the three colours of light a screen uses to build every image.
- Sublimation
- A solid turning straight into a gas, without becoming liquid first. Sublimation ink does this when heated, and so soaks into polyester or a coating.
- Transfer paper
- Paper on which the design is printed in mirror image, to be transferred to a mug or fabric with heat afterwards.
- Underbase
- A layer of white ink placed beneath the design in textile printing, so that colours stay bright on dark fabric.
Questions about printing
Will the print on my T-shirt fade in the wash?
Hardly. With direct-to-garment printing the ink sits inside the cotton fibres and is set with heat. Wash the shirt inside out on a cold cycle, and don't iron over the print. After a great many washes a print becomes a touch softer in colour, just like the cotton itself, but it won't crack or peel.
Can my printed mug go in the dishwasher?
Yes. With sublimation the design sits inside the mug's coating rather than on top of it, so there's nothing that can peel off. The colours stay bright. Only a magic mug, which reveals its design once it gets warm, should be washed by hand: that's down to its heat-sensitive layer, not the print.
What is the difference between DTG and sublimation?
With DTG a textile printer sprays ink straight into cotton, and heat then sets the ink. With sublimation the design is first printed on paper and then, with heat, carried as a gas into polyester or into the coating of a mug. DTG is for cotton, sublimation for polyester and coated materials.
What is the difference between DTG and DTF?
With DTG the ink goes straight into the cotton fibres. With DTF the design is first printed on a film and pressed onto the fabric with a layer of adhesive, so the print sits on the fabric as a thin layer. DTF works on almost any fabric; DTG feels softer and breathes better, which is why we use it for cotton.
Why don't you print cotton shirts with sublimation?
Sublimation ink only bonds with polyester. On cotton it has nothing to hold on to and washes out after a few washes. Sublimation has no white ink either, so on a coloured shirt your design would disappear.
Can you feel the print on a shirt?
On a white shirt hardly at all, because only coloured ink goes into the fabric there. On a coloured shirt there's a white underbase beneath the design, which you can feel as a soft layer on large areas. There's no film or plastic transfer on top.
How big does my photo need to be?
A recent 12-megapixel phone photo is plenty for a mug and for a full shirt front. On a blanket it gets enlarged, but you look at a blanket from a distance, so you won't notice.
Why are the colours different from my screen?
A screen makes colour with light, a printer with ink. Very bright screen colours, such as neon green or electric blue, don't exist in ink and come out a little calmer. The brightness of your screen and the material play a part too: cotton shows colours more softly than a glossy mug.