Can you iron polyester?

Polyester is a thermoplastic: it does not burn so much as melt, and it begins to soften well below the temperature a cotton setting reaches. A hot iron will glaze the surface into a permanent shiny patch, or weld the fabric to the soleplate. The low or synthetic setting, around 110 °C, is safe. Iron inside out with a pressing cloth or a thin tea towel between iron and garment, and use steam rather than pressure — polyester creases relax with moisture far more readily than with force.

How to do it properly

1. Set the iron to the lowest synthetic setting and let it stabilise.
2. Turn the garment inside out.
3. Put a thin cotton cloth between the iron and the fabric.
4. Keep the iron moving and use steam rather than pressing hard.

What goes wrong

• Too much heat leaves a permanent shiny glaze that cannot be reversed.
• The fabric can melt onto the soleplate and ruin both.

Other options

• Hang it in a steamy bathroom — most polyester creases drop out on their own.
• Use a garment steamer, which never touches the fabric.

Other "can you iron" questions

• Can you iron linen? Yes — Yes, on high heat with plenty of steam, while the fabric is still damp.
• Can you iron velvet? No — No. Pressing crushes the pile flat and it does not come back.