You can simply wash polyester in the washing machine at a maximum of 40 degrees. It is best to use the synthetic or delicate wash program. When you wash, it is a good idea to put them in the washing machine inside out. The fabric can generally also be tumble dried, but only at a low temperature. Maybe a few wrinkles will appear. You can iron it away with an iron. Make sure that you do not set the iron to too high a temperature. Otherwise you could damage your shirt. Polyester has all kinds of beneficial properties. This makes it breathable, does not wrinkle and the color remains beautiful for a long time. It also retains its shape and does not wear out quickly. Although polyester is a sturdy fabric, it still feels light to wear. And also nice, with a jacket. A breathable fabric Cotton and linen are popular fabrics because they absorb moisture well and feel nice on the body, but they do cause wet, dark stains. Polyester is a breathable fabric, just like polyamide. It does not absorb moisture, but sends it out. This way the moisture evaporates without leaving stains. This means you won’t get cold on a hot day, when the sun disappears and evening falls. The shirt then does exactly what you want: keeps you warm when necessary. If there was still moisture in the shirt, you could get cold from sweat. Sweating in polyester certainly does not happen. And that is very nice if you are looking for a shirt that can last for several seasons and years.