The sublimation Polyester fabric, generally speaking, is not a breathable fabric. When you wear a shirt or outfit made from 100% polyester, there is a possibility that you'll be sweating and uncomfortable by the end of the day.
There are some exceptions of course, so if you're planning to buy something that is 100% polyester, do a breathability test first if possible.
Fuchsia colored polyester fabric with close up of tag that says 100% polyester.
It is argued that polyester is not environmentally friendly. There is some truth to this because polyester will never disintegrate within a landfill. On the other hand, this means that polyester clothing can be donated, re-sold or re-cycled, so it is “green” in that sense.
Polyester is a flammable material, but the fabric is usually treated with fireproofing additives to help counteract this.
Polyester can be more expensive than natural fabrics because of its expensive production process - and it is tied to the price of crude oil.