I had been reading so much about how madelinetosh yarns are so lovely. I started dreaming that a friend visiting from the US soon would be able to bring me some, and I’d save money from imports/shipping etc. I wanted to get a “sweater quantity” because I do dream of being able to knit a garment someday, when I get out of the Garter Stitch Scarf Nursery.
I kept on reading reviews saying the wool “grows”, and saw photos of cardigans and jumpers that were unarguably looooong.
I got out the Knitters Book of Wool by Clara Parkes from the library.
She includes a detailed description of why wools have the textures, feel, lustre and whether or not it felts well: the scales.
Clara writes about how they make super wash wool, they basically remove the scales through a variety of processes. One for example is an enzyme that eats the scales so the yarn is smooth. This prevents the wool from felting when rubbed.
This is ALSO why super wash wool will tend to be so slippery that it stretches; there are no scales to grip to the others. That explains why the madelinetosh projects are growing out of proportion.
After reading that, I don’t think I’ll be making my first jumper out of super wash wool.
nearlythere 
Yep! For a first sweater, you should stay away. I am yet another person that has been burned by madelinetosh superwashes! Now I just don't wash them. I dry block and if the sweater needs freshening I spot clean the underarms and throw it on a pile of a snow for a few hours. (Of which I seem to have an unending supply. 😦 )