Dye sublimation works by heating special dyes so they turn into a gas and enter the polyester fibres, where they become part of the fibre when it cools. That is why sublimation prints on polyester are bright and feel like the fabric itself, with no layer on top. Cotton does not take these dyes in the same way. On a 50/50 blend, roughly only the polyester fibres hold the colour, and the cotton fibres stay largely uncoloured, so the print looks paler and slightly speckled.

Blend ratio matters

The higher the polyester content, the closer the result will be to a full polyester print. Many printers suggest a high polyester content for good sublimation results. Below that, colours lose depth, and dark colours are hard to achieve. The fabric must also be white or very light, since sublimation dyes are transparent and do not cover a coloured base.

Durability on blends

Even if the look is acceptable, check how it holds up. Wash samples with a named procedure such as ISO 6330, at your label conditions, and check colour change and staining with ISO 105-C06. Rubbing fastness under ISO 105-X12 and light fastness under ISO 105-B02 may also matter, depending on use. Results on the blend can differ from your polyester tees.

Alternatives for cotton-rich tees

For cotton or cotton-rich tees, other methods suit better. Direct-to-garment printing uses water-based inks designed for cotton and gives a soft hand feel. DTF transfers work on many fibres and handle multi-colour artwork. Screen printing is good for larger runs with fewer colours. All-over designs are harder on cotton; cut-and-sew from printed fabric may be an option for bigger quantities.

Decide on the fabric first

If the lifestyle range needs a cotton feel, choose the print method to suit the fabric. If the print look matters most, a polyester fabric with a soft finish or a cotton-touch polyester may be the compromise. Ask for samples of both before deciding.

Write it in the spec

Record the print method, fabric composition, colour fastness requirements and the approved washed sample in the decoration spec, so bulk is judged against the right reference.

Approve the artwork on the actual blend before committing to quantities, and keep that washed sample as the reference.