Sublimation only works on polyester
Dye sublimation bonds the ink into the fibre, which is why the print does not crack or peel. It only works on polyester, and the higher the polyester content the better the result. A cotton blend will produce a washed-out print, and the factory will produce it anyway if you ask.
This is the first specification: fibre composition, with a number. 100 percent polyester, or a named blend with the percentages fixed.
Fabric weight is what the customer feels
Measured in grams per square metre. A padel or tennis shirt sits typically between 130 and 160 gsm. Below that it feels cheap and shows sweat. Above it, it feels heavy. The factory will quote whatever number you name and will substitute a lighter fabric if you do not check, because gsm is cost.
Weigh a cut square from the bulk fabric, before cutting. This is a two-minute check that a factory will happily let you skip.
The failures nobody warns you about
Dye migration. Sublimated colour, especially deep reds and blues, can migrate into white panels over time, particularly in heat. Ask for a wash and heat test on the actual fabric, not on a swatch of something similar.
Seams. Flatlock seams on performance kit, not overlock, if you do not want chafing complaints. Check the stitch density.
Pilling. Cheap yarn pills after five washes. A Martindale abrasion test result is the number to ask for.
How to approve it
Approve bulk fabric before cutting, not a swatch. Approve a sewn sample in the actual size run. Wash it five times yourself. Then seal it as the golden sample and reference it in the contract.
Every step of that costs a week. Skipping any of them costs a season.
- Sublimation needs polyester. Fix the fibre composition as a number in the contract.
- Fabric weight in gsm is the cost lever and the feel. Weigh the bulk fabric.
- Test dye migration, seam type and pilling on the real fabric, not on a swatch.
- Approve bulk fabric before cutting. After the roll is on the table, nobody stops the line.
