Ya know there's a new acrylic out there called TLC (I think it's made by red heart. It has a picutre of a little kitty cat on it) but it doesn't feel like fiberglass.
I've worked with TLC CaraMia and it's soft and wonderful and makes great, warm, hats and scarves, etc. Looking at a leftover label, it's a cold water, gentle cycle, machine washable, medium, worsted weight yarn:
50% Acrylic, 19% Nylon, 18% Rayon, 13% Angora
One note of caution. For Xmas presents, I made 2 black/white combo scarves with Charcoal & Winter White. While washing in plain, ice cold water to block, I had a major dye bleed problem with Charcoal. I ended up with 2 (still adorable puppy themed) black/grey scarves. An old Red Heart acrylic fan myself, who'd have "thunk" it about dye bleed? I guess we all have to live and learn and boy, did I. :x
I called and wrote Coats and Clark (yes, they were very concerned) and was sent an envelope to enclose samples of the washed and unwashed yarn. I'm told I'll be receiving replacements skein's as an apology and thank you for reporting the problem.
Been about a month since I submitted the samples, but I'm patient and glad to know an American company is standing behind their product. Since I sent in the color's skein labels, I have to rely on memory....I think they were dyed in Mexico.
I'd recommend a hat using CaraMia, it's very soft and pliable as yarns go, although perhaps a tiny bit snaggy on the (Red Heart Crystalite) crochet hook I used. Because of my personal experience, I'd play it "better safe than sorry" with any of the TLC dark yarns for now anyway. Be sure to test your gauge swatch for colorfastness in a cold hand wash prior to making a complete project.