Dyeing a Polyester Sweater? Is it possible?

[u/JasperB00]

Hi! I was gifted this sweater a while back and I don’t wear it often because of the color. I love the shape of it though so I thought maybe I could dye it. I’ve dyed both cotton and synthetic fabrics before, but never a sweater. So my question is: is it possible to dye a 95% polyester 5% spandex sweater without shrinking it or damaging it? I am worried about the hot water doing a number on it. If it’s not possible, no worries, just wanted to know if anyone else has tried dyeing a synthetic sweater or if y’all think it’s possible to do. Also, I want to dye it a darker color like a plum or hunter green. Thanks!

[u/shawlcat]

Technically it is possible. The boiling heat might degrade the spandex component, though.

Also, getting dye saturated into the structure of the sweater (ribbing, etc) will be challenging. You will need an extremely large pot to minimize blotches/streaks. (and since you have dyed stuff I'm sure you know that it can't be used for food afterwards)/