Print the flat model, lay it on the shirt under baking parchment and press it with an iron. Below is the whole process with numbers: what to print, how hot, how long, and how to wash it afterwards.
Try it on a scrap or an old shirt first. The iron runs at maximum, and synthetics melt at that temperature — check the care label, you want cotton.
It bends with the fabric and survives dozens of washes. Nozzle 225 °C, bed 45–60 °C, 100 % infill, no supports, outer wall slower: around 30 mm/s. Anywhere from one to four layers of 0.2 mm — how many depends on the spool. Some filaments hold from a single layer, others need four; start with two and see how the edge behaves.
Easy to print and cheap, but stiff. One or two layers still flex; thicker than that and it cracks at the fold and lifts after a few washes. Fine for a test, worse for wearing.
Lay parchment on the bed and hold it down with clips; a glue stick helps. Printing straight onto the paper gives a flat underside and comes away without chipping.
If the model has lettering, mirror it in the slicer: the print goes onto the shirt face-down.
Run the iron over the spot for 10–15 seconds. That takes out the creases and the last of the moisture — plastic will not bond to damp fabric.
The side that faced up during printing goes against the fabric: its layer lines key into the fibres. The smooth parchment side stays outward and is the one you will see.
A clean one, not the sheet you printed on. It keeps the plastic off the soleplate and spreads the heat more evenly.
Maximum heat, steam off. Lean on it with your body rather than your arm, and lift-and-place the iron instead of sliding it about. Then lift a corner: if the print comes away, give it another 15 seconds.
Do not peel it hot: warm plastic stretches and tears at the edge. Put a book on top and leave it a few minutes until everything is at room temperature.
Cold paper lifts by itself. If it clings anywhere, warm that spot for another 10 seconds and cool it under weight again.
| What you see | What to do |
|---|---|
| The print lifts at an edge | Too little time or pressure. Cover it, warm that edge for another 15–20 seconds and cool it under weight. |
| Fine detail has smeared | TPU spreads under pressure. Print thinner — two layers instead of four — and hold the iron for 20 seconds rather than 30. |
| The fabric scorched | There is synthetic in the shirt. Drop the heat one step and go up to 45 seconds — or better, use pure cotton. |
| The print cracked after washing | That is PLA: stiff, and it breaks at folds. Switch to TPU. |
Upload a drawing — the service works out the millimetres and checks the thickness against your nozzle.