A synthetic fiber - a man-made polymer, PET or just "some kind of plastic fiber" - and one of the most popular fibers world wide, used in some form in many different industries.
Originally known as a cheap and uncomfortable fabric, mixing it with other fibers removes these disadvantages. Most clothes have a least some percentage of Polyester. It is quick drying, has a stable form, high durability and can easily be dyed.
In more recent time the popularity of recycled polyester is at an all time high. While polyester - as most plastics - are not biodegradable, it can more easily be recycled and made into new fabric. See PET bottle recycling for example.
CHANTY mixes in some Polyester to allow for special dyeing techniques, otherwise unachievable, as Polyester takes to dyes extremely well. This is done on special customer requests.
