I had a textiles teacher in college who told us that if she could rename her daughters they would be Poly and Esther in honour, of course, of Polyester. There is nothing you couldn't do with or to the fabric and still not ruin it. (never mind its extreme flammability).
When knitting you want to knit with yarn that is washable most of the time. Especially if its a gift for a child. However, wool feels so nice. Sometimes synthetic feels synthetic. (but not all does)
But synthetic equals more economical and machine wash and dry.
Wool equals great feel to the touch and either hand wash or at least gentle cycle with lay flat to dry.
There are also cotton blends but I'm not going to get that detailed!
Today though, Debbie Stoller, the author of Stitch 'N Bitch posted that she's got a Washable Ewe wool! I know there's others out there, like the one I bought by Liberty Wool, but I wanted to share with you.
(click below for a preview of her colours)